In this chapter, we examine the effect of audio computer-assisted self-interviewing (ACASI) experimental factors on reported prevalence, inconsistencies in reporting, time required to complete the interview, and breakoff rates. In addition, we examine the effect that the experimental factors had on respondents' ability to complete the interview and their attitudes about the survey task. Sections 7.1 through 7.3 contain the descriptive results; in Sections 7.4 and 7.5, we present the results of the statistical tests.
Because all respondents did not answer the same questions, it was necessary to create a set of edited recency of use variables for constructing the lifetime, 12-month, and 30-day prevalence of use estimates. This was done in three stages. In the ACASI application, all respondents had multiple chances to report use. For example, even respondents who did not receive multiple use questions could report that they had used alcohol in the past 30 days and subsequently report that they had used it on 0 days in the past 30 days. And some respondents who were in the multiple use treatment category were asked twice about their use in a particular time period. Thus, we first created a series of recodes for 30-day and 12-month use that documented whether the respondent was consistent or inconsistent in reporting use in these time periods. For example, we created a variable MU30ALC that had the following four levels:
For the random half of the respondents who received consistency checks during the interview and who had inconsistent data (e.g., MU30ALC = 2 or 3), we created a variable that documented the outcome of the consistency check. This variable also had four levels based on the path through the questionnaire and classified the respondent as either a user or nonuser for the period in question. The edited recency variables were created from these intermediate recodes.
This process resulted in our inability to determine the recency of use of some respondents; therefore, we had a residual category of indeterminate answers. In the NHSDA series of surveys, a similar logical editing procedure is used; however, before the final estimates are made, all indeterminate recency of use answers are removed by statistical imputation. We did not use any statistical imputations for the field experiment analysis. Therefore, when we compared 1997 field experiment data with data from the 1997 NHSDA Quarter 4, we used the recency variable thatwas edited but not imputed because it was the most analogous paper-and pencil interview (PAPI) comparison variable.
For cigarettes, there is one final important difference between the field experiment and the 1997 NHSDA that affects the prevalence estimates. In the field experiment, we routed respondents who had only had one or two puffs of a cigarette to the next section after they had reported their age at first use.
In addition to the edited variables, we also produced tables of weighted estimates using raw variables that were created using the most direct question on recency of use. For example, respondents in Treatments 5, 6, 7, and 8 who answered "yes" to the question "During the past 30 days, have you _______?" were counted as 30-day users even if they later indicated having used 0 days in the past 30 days. For the comparison group, we used answers to the recency question "How long has it been since you last used ______?" to create the raw variables. Estimates using raw variables are given in RTI (1998).
Exhibit 7.1 summarizes the findings for the main effects of the ACASI experimental factors by showing the ratios of the prevalence estimates by the level of the main effects. In the following section, each factor is discussed separately, followed by the results of the modeling.
7.1 Structure of Contingent Questioning
As described in Chapter 5, a random half of the respondents received a single gate question and a random half received three gate questions. We hypothesized that using multiple gate questions would result in fewer inconsistent reports and higher reports of prevalence of use, particularly for lifetime and 12-month use. We speculated that lifetime prevalence might be higher because (a) respondents could first deny more proximate use, which other research (e.g., Turner, Lessler, & Devore, 1992a) has shown to be a more sensitive behavior, and (b) it would prevent routing respondents who inadvertently answered "no" to a single gate question to the next section, thereby missing a chance to gather information about their use. In addition, we felt that having multiple gate questions that permitted the respondent to focus on each reference period individually would reduce inconsistencies in reporting.
7.1.1 Prevalence Estimates
Exhibits 7.1.1 through 7.1.15 display the weighted estimates of prevalence by selected demographic variables. For cigarette use, a mixed pattern was observed in the overall estimates, with single gate questions sometimes yielding higher reports and sometimes yielding lower reports. Differences between the two approaches were not large in any case, and most ratios were close to one. A similar pattern was observed for alcohol use. For marijuana, cocaine, and any illicit drug use, the single gate questions tended to yield higher reports of use. These findings were not in the direction hypothesized prior to the field experiment.
7.1.2 Inconsistencies in Reporting
We also examined inconsistencies in reporting by identifying the number of people who had a chance to give an inconsistent report. We confined this detailed analysis to cigarettes, alcohol, and marijuana so that we would have enough people to make meaningful comparisons. Exhibits 7.1.16 to 7.1.20, contrary to our expectations, indicate that multiple gate questions resulted in a higher percentages of inconsistent reports in most of the cases compared to single gate questions. The denominators (N) of the percentages included people who were able to get to the questions (i.e., they were not routed to the next section at a previous question), where they recorded the number of days of use within the particular time period. For past 12-month use, respondents answering the treatment versions with no multiple use questions had no chance of recording an inconsistent response.
7.1.3 Operational Aspects of Reporting Under Alternative Contingent Questioning Strategies
Time required to complete the interview. The average length of time required to complete each drug section with multiple gate questions was slightly higher than the time required to complete each drug section with a single gate question. However, the differences were not large (see Exhibit 7.1.21).
Exhibit 7.1 Ratio of Prevalence Estimates for ACASI Experimental Factors Overall and by Age Group | |||||||||||
Overall |
18+ Years Old |
12 to 17 Years Old | |||||||||
Factor |
Lifetime |
12 Month |
30 Day |
Lifetime |
12 Month |
30 Day |
Lifetime |
12 Month |
30 Day | ||
Cigarettes |
|||||||||||
Multiple Gate Qs: Single/Multiple |
1.07 |
0.87 |
1.03 |
1.08 |
0.87 |
1.03 |
0.94 |
0.99 |
1.07 | ||
Multiple 30-Day and 12-Month Qs: Consistency Checks: |
0.94 |
0.84 |
0.77 |
0.93 |
0.82 |
0.76 |
1.05 |
1.09 |
0.92 | ||
Alcohol | |||||||||||
Multiple Gate Qs: Single/Multiple |
0.97 |
0.90 |
0.94 |
0.97 |
0.90 |
0.94 |
1.00 |
1.00 |
1.05 | ||
Multiple 30-Day and 12-Month Qs: Consistency Checks: |
0.97 |
0.91 |
0.85 |
1.03 |
1.03 |
0.89 |
0.97 |
0.90 |
0.85 | ||
Marijuana | |||||||||||
Multiple Gate Qs: Single/Multiple |
1.01 |
1.63 |
1.45 |
1.00 |
1.76 |
1.48 |
1.18 |
1.12 |
1.32 | ||
Multiple 30-Day and 12-Month Qs: Consistency Checks: |
0.99 |
0.94 |
0.64 |
0.99 |
0.94 |
0.59 |
1.02 |
0.94 |
0.85 | ||
Cocaine | |||||||||||
Multiple Gate Qs: Single/Multiple |
1.93 |
2.64 |
1.13 |
1.94 |
2.76 |
1.00 |
1.92 |
1.86 |
3.77 | ||
Multiple 30-Day and 12-Month Qs: Consistency Checks: |
0.62 |
0.75 |
1.09 |
0.63 |
0.74 |
0.95 |
0.74 |
0.96 |
4.68 | ||
Any Illicit Drug1 | |||||||||||
Multiple Gate Qs: Single/Multiple |
1.14 |
1.29 |
1.45 |
1.13 |
1.34 |
1.51 |
1.18 |
1.06 |
1.23 | ||
Multiple 30-Day and 12-Month Qs: Consistency Checks: |
0.99 |
0.92 |
0.64 |
0.99 |
0.93 |
0.60 |
0.98 |
0.84 |
0.76 | ||
1Any illicit drug includes marijuana, cocaine, crack, heroin, inhalants, hallucinogens, and nonmedical use of analgesics, sedatives, stimulants, and tranquilizers.
Source: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures: 1997 Field Experiment.
Breakoff rates. In Exhibit 7.1.22, we compared the percentage of cases that were reported as a breakoff (even if the interviewer went on to finalize the case as a completed interview) by the treatment versions (single gate vs. multiple gate questions). Then we compared the percentage of finalized breakoff cases among single rate and multiple gate questions. The data show no meaningful difference between the breakoff rates for single gate and multiple gate questions.
Respondent reactions as reported in the debriefing questionnaire. Exhibit 7.1.23 presents an analysis of items from the respondent debriefing questions to see whether multiple gate questions had any effect on respondent reactions to the computer-assisted interviewing (CAI) NHSDA interview. The exhibit includes data from five items. About 87% of the respondents who were administered the multiple gate questions indicated that they were able to enter answers easily into the computer compared to 90% of the respondents who were administered the single gate questions. There was no important difference between the responses for single gate and multiple gate questions for the other items, including respondents' difficulty in using the computer, their interest in the interview, and the accuracy and completeness of their answers.
Exhibit 7.1.1 Lifetime Use of Cigarettes, by Contingent Questioning Structure | ||||
Respondent Characteristics |
ACASI Treatment Groups |
Comparison Group | ||
Single Gate Questions |
Multiple Gate Questions |
Total ACASI |
1997 | |
Treatment Version: |
1, 2, 3, 4 |
5, 6, 7, 8 | ||
Total |
74.18% |
69.38% |
71.96% |
70.87% |
Age Group |
||||
12 to 17 |
43.20% |
46.04% |
44.48% |
36.05% |
18+ |
77.88% |
72.04% |
75.18% |
74.94% |
Gender |
||||
Male |
75.71% |
72.64% |
74.25% |
74.74% |
Female |
72.82% |
66.14% |
69.83% |
67.25% |
Race/Ethnicity |
||||
Hispanic |
64.34% |
63.15% |
63.68% |
55.82% |
Non-Hisp., Black |
62.65% |
66.11% |
64.30% |
61.62% |
Non-Hisp., All Other Races |
76.82% |
70.65% |
74.04% |
73.81% |
Education1 |
||||
< High School |
84.90% |
68.25% |
77.83% |
70.28% |
High School |
78.43% |
81.58% |
79.73% |
76.65% |
> High School |
75.01% |
67.77% |
71.35% |
75.27% |
1Education includes only individuals aged 18 or older.
Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.1.2 Lifetime Use of Alcohol, by Contingent Questioning Structure | ||||
Respondent Characteristics |
ACASI Treatment Groups |
Comparison Group | ||
Single Gate Questions |
Multiple Gate Questions |
Total ACASI |
1997 | |
Treatment Version: |
1, 2, 3, 4 |
5, 6, 7, 8 | ||
Total |
82.01% |
84.50% |
83.16% |
82.15% |
Age Group |
||||
12 to 17 |
44.89% |
44.92% |
44.90% |
38.01% |
18+ |
86.45% |
89.01% |
87.63% |
87.31% |
Gender |
||||
Male |
80.10% |
88.20% |
83.95% |
87.07% |
Female |
83.70% |
80.81% |
82.41% |
77.55% |
Race/Ethnicity |
||||
Hispanic |
70.87% |
77.01% |
74.26% |
69.45% |
Non-Hisp., Black |
65.91% |
65.13% |
65.54% |
72.35% |
Non-Hisp., All Other Races |
85.51% |
88.92% |
87.04% |
84.98% |
Education1 |
||||
< High School |
84.79% |
78.92% |
82.30% |
77.22% |
High School |
81.23% |
89.67% |
84.73% |
85.83% |
> High School |
91.16% |
91.17% |
91.16% |
91.48% |
1Education includes only individuals aged 18 or older.
Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.1.3 Lifetime Use of Marijuana, by Contingent Questioning Structure | ||||
Respondent Characteristics |
ACASI Treatment Groups |
Comparison Group | ||
Single Gate Questions |
Multiple Gate Questions |
Total ACASI |
1997 | |
Treatment Version: |
1, 2, 3, 4 |
5, 6, 7, 8 | ||
Total |
35.36% |
34.98% |
35.18% |
34.96% |
Age Group |
||||
12 to 17 |
22.08% |
18.70% |
20.56% |
16.10% |
18+ |
36.94% |
36.84% |
36.90% |
37.17% |
Gender |
||||
Male |
39.35% |
36.06% |
37.78% |
40.79% |
Female |
31.81% |
33.91% |
32.75% |
29.51% |
Race/Ethnicity |
||||
Hispanic |
38.98% |
39.12% |
39.06% |
24.59% |
Non-Hisp., Black |
27.72% |
34.49% |
30.95% |
31.43% |
Non-Hisp., All Other Races |
36.39% |
34.63% |
35.60% |
36.48% |
Education1 |
||||
< High School |
26.55% |
29.61% |
27.85% |
32.84% |
High School |
36.22% |
35.84% |
36.06% |
36.60% |
> High School |
41.12% |
39.19% |
40.15% |
38.91% |
1Education includes only individuals aged 18 or older.
Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.1.4 Lifetime Use of Cocaine, by Contingent Questioning Structure | ||||
Respondent Characteristics |
ACASI Treatment Groups |
Comparison Group | ||
Single Gate Questions |
Multiple Gate Questions |
Total ACASI |
1997 | |
Treatment Version: |
1, 2, 3, 4 |
5, 6, 7, 8 | ||
Total |
19.18% |
9.93% |
14.91% |
10.03% |
Age Group |
||||
12 to 17 |
3.64% |
1.90% |
2.86% |
3.13% |
18+ |
21.04% |
10.84% |
16.32% |
10.84% |
Gender |
||||
Male |
26.68% |
9.70% |
18.60% |
12.47% |
Female |
12.53% |
10.15% |
11.46% |
7.76% |
Race/Ethnicity |
||||
Hispanic |
15.81% |
18.52% |
17.30% |
7.32% |
Non-Hisp., Black |
15.27% |
4.02% |
9.90% |
7.57% |
Non-Hisp., All Other Races |
20.08% |
10.12% |
15.59% |
10.70% |
Education1 |
||||
< High School |
36.36% |
8.47% |
24.51% |
9.52% |
High School |
17.54% |
9.64% |
14.27% |
10.37% |
> High School |
18.50% |
12.09% |
15.26% |
11.58% |
1Education includes only individuals aged 18 or older.
Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.1.5 Lifetime Use of Any Illicit Drug, by Contingent Questioning Structure | ||||
Respondent Characteristics |
ACASI Treatment Groups |
Comparison Group | ||
Single Gate Questions |
Multiple Gate Questions |
Total ACASI |
1997 | |
Treatment Version: |
1, 2, 3, 4 |
5, 6, 7, 8 | ||
Total |
46.26% |
40.75% |
43.72% |
37.50% |
Age Group |
||||
12 to 17 |
33.48% |
28.32% |
31.15% |
20.45% |
18+ |
47.79% |
42.17% |
45.19% |
39.49% |
Gender |
||||
Male |
49.68% |
37.16% |
43.72% |
43.44% |
Female |
43.23% |
44.32% |
43.72% |
31.94% |
Race/Ethnicity |
||||
Hispanic |
46.31% |
42.58% |
44.25% |
28.63% |
Non-Hisp., Black |
34.56% |
38.82% |
36.59% |
33.40% |
Non-Hisp., All Other Races |
48.23% |
40.92% |
44.93% |
38.99% |
Education1 |
||||
< High School |
54.09% |
32.81% |
45.05% |
37.22% |
High School |
46.31% |
44.03% |
45.36% |
38.42% |
> High School |
46.79% |
43.49% |
45.12% |
40.92% |
1Education includes only individuals aged 18 or older.
Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.1.6 Past 12-Month Use of Cigarettes, by Contingent Questioning Structure | ||||
Respondent Characteristics |
ACASI Treatment Groups |
Comparison Group | ||
Single Gate Questions |
Multiple Gate Questions |
Total ACASI |
1997 | |
Treatment Version: |
1, 2, 3, 4 |
5, 6, 7, 8 | ||
Total |
29.24% |
33.46% |
31.19% |
33.52% |
Age Group |
||||
12 to 17 |
22.74% |
23.05% |
22.88% |
25.18% |
18+ |
30.02% |
34.65% |
32.16% |
34.49% |
Gender |
||||
Male |
38.14% |
33.32% |
35.85% |
34.17% |
Female |
21.34% |
33.59% |
26.82% |
32.91% |
Race/Ethnicity |
||||
Hispanic |
34.51% |
23.70% |
28.55% |
32.69% |
Non-Hisp., Black |
24.35% |
36.07% |
29.94% |
35.19% |
Non-Hisp., All Other Races |
29.69% |
34.01% |
31.64% |
33.29% |
Education1 |
||||
< High School |
57.88% |
28.04% |
45.20% |
34.76% |
High School |
24.86% |
51.87% |
36.04% |
41.55% |
High School |
24.44% |
26.87% |
25.67% |
29.70% |
1Education includes only individuals aged 18 or older.
Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.1.7 Past 12-Month Use of Alcohol, by Contingent Questioning Structure | ||||
Respondent Characteristics |
ACASI Treatment Groups |
Comparison Group | ||
Single Gate Questions |
Multiple Gate Questions |
Total ACASI |
1997 | |
Treatment Version: |
1, 2, 3, 4 |
5, 6, 7, 8 | ||
Total |
65.11% |
71.99% |
68.28% |
64.95% |
Age Group |
||||
12 to 17 |
36.42% |
36.49% |
36.45% |
32.74% |
18+ |
68.54% |
76.03% |
72.00% |
68.71% |
Gender |
||||
Male |
62.83% |
77.43% |
69.78% |
70.07% |
Female |
67.12% |
66.58% |
66.88% |
60.15% |
Race/Ethnicity |
||||
Hispanic |
54.39% |
71.17% |
63.65% |
57.10% |
Non-Hisp., Black |
44.86% |
56.29% |
50.31% |
53.54% |
Non-Hisp., All Other Races |
69.27% |
75.01% |
71.86% |
67.64% |
Education1 |
||||
< High School |
57.94% |
50.08% |
54.60% |
48.54% |
High School |
66.10% |
77.46% |
70.80% |
68.12% |
> High School |
74.15% |
81.74% |
77.99% |
75.47% |
1Education includes only individuals aged 18 or older.
Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.1.8 Past 12-Month Use of Marijuana, by Contingent Questioning Structure | ||||
Respondent Characteristics |
ACASI Treatment Groups |
Comparison Group | ||
Single Gate Questions |
Multiple Gate Questions |
Total ACASI |
1997 | |
Treatment Version: |
1, 2, 3, 4 |
5, 6, 7, 8 | ||
Total |
12.47% |
7.64% |
10.24% |
9.36% |
Age Group |
||||
12 to 17 |
17.56% |
15.62% |
16.69% |
12.97% |
18+ |
11.86% |
6.73% |
9.49% |
8.94% |
Gender |
||||
Male |
17.80% |
9.62% |
13.91% |
13.08% |
Female |
7.75% |
5.68% |
6.82% |
5.88% |
Race/Ethnicity |
||||
Hispanic |
10.71% |
16.66% |
13.99% |
10.21% |
Non-Hisp., Black |
8.84% |
7.73% |
8.31% |
9.60% |
Non-Hisp., All Other Races |
13.21% |
6.67% |
10.26% |
9.25% |
Education1 |
||||
< High School |
10.89% |
4.19% |
8.05% |
14.87% |
High School |
9.05% |
7.95% |
8.59% |
10.10% |
> High School |
14.43% |
6.70% |
10.52% |
6.30% |
1Education includes only individuals aged 18 or older.
Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.1.9 Past 12-Month Use of Cocaine, by Contingent Questioning Structure | ||||
Respondent Characteristics |
ACASI Treatment Groups |
Comparison Group | ||
Single Gate Questions |
Multiple Gate Questions |
Total ACASI |
1997 | |
Treatment Version: |
1, 2, 3, 4 |
5, 6, 7, 8 | ||
Total |
3.69% |
1.40% |
2.63% |
1.60% |
Age Group |
||||
12 to 17 |
2.23% |
1.20% |
1.77% |
2.54% |
18+ |
3.87% |
1.42% |
2.74% |
1.49% |
Gender |
||||
Male |
4.80% |
1.16% |
3.07% |
2.10% |
Female |
2.71% |
1.64% |
2.23% |
1.13% |
Race/Ethnicity |
||||
Hispanic |
6.72% |
2.91% |
4.62% |
1.56% |
Non-Hisp., Black |
4.31% |
2.41% |
3.40% |
2.98% |
Non-Hisp., All Other Races |
3.37% |
1.05% |
2.33% |
1.36% |
Education1 |
||||
< High School |
7.53% |
2.01% |
5.19% |
1.87% |
High School |
1.59% |
2.25% |
1.86% |
2.03% |
> High School |
4.41% |
0.82% |
2.59% |
1.01% |
1Education includes only individuals aged 18 or older.
Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.1.10 Past 12-Month Use of Any Illicit Drug, by Contingent Questioning Structure | ||||
Respondent Characteristics |
ACASI Treatment Groups |
Comparison Group | ||
Single Gate Questions |
Multiple Gate Questions |
Total ACASI |
1997 | |
Treatment Version: |
1, 2, 3, 4 |
5, 6, 7, 8 | ||
Total |
16.92% |
13.10% |
15.16% |
10.28% |
Age Group |
||||
12 to 17 |
23.70% |
22.22% |
23.03% |
14.54% |
18+ |
16.10% |
12.07% |
14.24% |
9.78% |
Gender |
||||
Male |
20.97% |
11.04% |
16.24% |
13.87% |
Female |
13.32% |
15.16% |
14.14% |
6.93% |
Race/Ethnicity |
||||
Hispanic |
17.84% |
22.11% |
20.20% |
12.33% |
Non-Hisp., Black |
14.43% |
10.90% |
12.74% |
9.99% |
Non-Hisp., All Other Races |
17.27% |
12.56% |
15.15% |
10.16% |
Education1 |
||||
< High School |
15.60% |
6.03% |
11.53% |
14.57% |
High School |
11.81% |
16.32% |
13.68% |
10.63% |
> High School |
19.69% |
11.25% |
15.41% |
7.71% |
1Education includes only individuals aged 18 or older.
Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.1.11 Past 30-Day Use of Cigarettes, by Contingent Questioning Structure | ||||
Respondent Characteristics |
ACASI Treatment Groups |
Comparison Group | ||
Single Gate Questions |
Multiple Gate Questions |
Total ACASI |
1997 | |
Treatment Version: |
1, 2, 3, 4 |
5, 6, 7, 8 | ||
Total |
26.61% |
25.73% |
26.20% |
30.45% |
Age Group |
||||
12 to 17 |
16.62% |
15.49% |
16.11% |
18.56% |
18+ |
27.80% |
26.89% |
27.38% |
31.84% |
Gender |
||||
Male |
34.95% |
21.26% |
28.43% |
31.10% |
Female |
19.20% |
30.17% |
24.11% |
29.84% |
Race/Ethnicity |
||||
Hispanic |
30.09% |
21.46% |
25.33% |
28.86% |
Non-Hisp., Black |
18.94% |
31.21% |
24.79% |
33.03% |
Non-Hisp., All Other Races |
27.65% |
25.15% |
26.53% |
30.13% |
Education1 |
||||
< High School |
57.32% |
26.00% |
44.01% |
34.23% |
High School |
23.07% |
45.24% |
32.25% |
38.72% |
> High School |
21.31% |
17.08% |
19.17% |
26.50% |
1Education includes only individuals aged 18 or older.
Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.1.12 Past 30-Day Use of Alcohol, by Contingent Questioning Structure | ||||
Respondent Characteristics |
ACASI Treatment Groups |
Comparison Group | ||
Single Gate Questions |
Multiple Gate Questions |
Total ACASI |
1997 | |
Treatment Version: |
1, 2, 3, 4 |
5, 6, 7, 8 | ||
Total |
47.35% |
50.27% |
48.70% |
52.21% |
Age Group |
||||
12 to 17 |
17.43% |
16.60% |
17.06% |
18.84% |
18+ |
50.93% |
54.11% |
52.40% |
56.11% |
Gender |
||||
Male |
47.93% |
54.42% |
51.02% |
60.23% |
Female |
46.83% |
46.15% |
46.53% |
44.70% |
Race/Ethnicity |
||||
Hispanic |
38.07% |
37.65% |
37.84% |
40.79% |
Non-Hisp., Black |
27.70% |
43.45% |
35.21% |
41.19% |
Non-Hisp., All Other Races |
51.31% |
52.89% |
52.02% |
55.15% |
Education1 |
||||
< High School |
38.35% |
20.71% |
30.85% |
40.55% |
High School |
43.74% |
53.18% |
47.65% |
55.62% |
> High School |
60.99% |
62.97% |
61.99% |
61.34% |
1Education includes only individuals aged 18 or older.
Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.1.13 Past 30-Day Use of Marijuana, by Contingent Questioning Structure | ||||
Respondent Characteristics |
ACASI Treatment Groups |
Comparison Group | ||
Single Gate Questions |
Multiple Gate Questions |
Total ACASI |
1997 | |
Treatment Version: |
1, 2, 3, 4 |
5, 6, 7, 8 | ||
Total |
5.54% |
3.82% |
4.74% |
5.28% |
Age Group |
||||
12 to 17 |
9.39% |
7.12% |
8.37% |
7.30% |
18+ |
5.08% |
3.44% |
4.32% |
5.04% |
Gender |
||||
Male |
8.24% |
5.66% |
7.01% |
7.30% |
Female |
3.14% |
1.99% |
2.62% |
3.39% |
Race/Ethnicity |
||||
Hispanic |
6.04% |
1.95% |
3.79% |
4.48% |
Non-Hisp., Black |
4.94% |
4.10% |
4.54% |
6.05% |
Non-Hisp., All Other Races |
5.60% |
3.96% |
4.86% |
5.21% |
Education1 |
||||
< High School |
6.24% |
3.44% |
5.05% |
10.13% |
High School |
4.94% |
3.16% |
4.21% |
5.92% |
> High School |
4.78% |
3.59% |
4.18% |
2.86% |
1Education includes only individuals aged 18 or older.
Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.1.14 Past 30-Day Use of Cocaine, by Contingent Questioning Structure | ||||
Respondent Characteristics |
ACASI Treatment Groups |
Comparison Group | ||
Single Gate Questions |
Multiple Gate Questions |
Total ACASI |
1997 | |
Treatment Version: |
1, 2, 3, 4 |
5, 6, 7, 8 | ||
Total |
0.60% |
0.53% |
0.57% |
0.59% |
Age Group |
||||
12 to 17 |
0.98% |
0.26% |
0.66% |
1.09% |
18+ |
0.56% |
0.56% |
0.56% |
0.53% |
Gender |
||||
Male |
0.51% |
0.35% |
0.43% |
0.61% |
Female |
0.68% |
0.71% |
0.69% |
0.56% |
Race/Ethnicity |
||||
Hispanic |
1.79% |
1.09% |
1.40% |
0.80% |
Non-Hisp., Black |
0.70% |
1.39% |
1.03% |
2.09% |
Non-Hisp., All Other Races |
0.50% |
0.31% |
0.41% |
0.30% |
Education1 |
||||
< High School |
2.19% |
0.92% |
1.65% |
0.87% |
High School |
0.54% |
0.84% |
0.67% |
0.89% |
> High School |
0.00% |
0.31% |
0.16% |
0.18% |
1Education includes only individuals aged 18 or older.
Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.1.15 Past 30-Day Use of Any Illicit Drug, by Contingent Questioning Structure | ||||
Respondent Characteristics |
ACASI Treatment Groups |
Comparison Group | ||
Single Gate Questions |
Multiple Gate Questions |
Total ACASI |
1997 | |
Treatment Version: |
1, 2, 3, 4 |
5, 6, 7, 8 | ||
Total |
6.91% |
4.75% |
5.91% |
5.44% |
Age Group |
||||
12 to 17 |
13.02% |
10.63% |
11.95% |
7.98% |
18+ |
6.18% |
4.08% |
5.21% |
5.14% |
Gender |
||||
Male |
9.30% |
6.89% |
8.15% |
7.68% |
Female |
4.80% |
2.62% |
3.82% |
3.34% |
Race/Ethnicity |
||||
Hispanic |
7.30% |
3.16% |
5.02% |
4.60% |
Non-Hisp., Black |
6.76% |
6.76% |
6.76% |
6.45% |
Non-Hisp., All Other Races |
6.91% |
4.54% |
5.84% |
5.33% |
Education1 |
||||
< High School |
7.66% |
4.42% |
6.28% |
9.46% |
High School |
5.89% |
3.97% |
5.09% |
5.94% |
> High School |
5.90% |
4.05% |
4.97% |
3.25% |
1Education includes only individuals aged 18 or older.
Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.1.16 Past 30-Day Use of Cigarettes: Percentage of Inconsistent Respondents | ||||||||||
Single Gate Questions |
Multiple Gate Questions |
|||||||||
Multiple Use Questions Absent |
Multiple Use Questions Present |
Multiple Use Questions Absent |
Multiple Use Questions Present |
Total ACASI | ||||||
Type of Inconsistency |
Sample |
% |
Sample |
% |
Sample |
% |
Sample |
% |
Sample |
% |
Total |
2 |
1.82 |
12 |
7.90 |
6 |
5.66 |
14 |
10.94 |
34 |
6.86 |
"Yes" to Period; 0 Days Reported |
2 |
1.82 |
5 |
3.29 |
6 |
5.66 |
14 |
10.94 |
27 |
5.44 |
"No" to Period; Greater Than 0 Days Reported |
N/A |
7 |
4.61 |
N/A |
0 |
0.00 |
7 |
1.41 | ||
Source: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment.
Exhibit 7.1.17 Past 30-Day Use of Alcohol: Percentage of Inconsistent Respondents | ||||||||||
Single Gate Questions |
Multiple Gate Questions |
|||||||||
Multiple Use Questions Absent |
Multiple Use Questions Present |
Multiple Use Questions Absent |
Multiple Use Questions Present |
Total ACASI | ||||||
Type of Inconsistency |
Sample |
% |
Sample |
% |
Sample |
% |
Sample |
% |
Sample |
% |
Total |
11 |
6.43 |
25 |
9.43 |
19 |
11.05 |
26 |
12.21 |
81 |
9.87 |
"Yes" to Period; 0 Days Reported |
11 |
6.43 |
14 |
5.28 |
19 |
11.05 |
13 |
6.10 |
57 |
6.94 |
"No" to Period; Greater Than 0 Days Reported |
N/A |
11 |
4.15 |
N/A |
13 |
6.10 |
24 |
2.92 | ||
Source: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment.
Exhibit 7.1.18 Past 30-Day Use of Marijuana: Percentage of Inconsistent Respondents | ||||||||||
Single Gate Questions |
Multiple Gate Questions |
|||||||||
Multiple Use Questions Absent |
Multiple Use Questions Present |
Multiple Use Questions Absent |
Multiple Use Questions Present |
Total ACASI | ||||||
Type of Inconsistency |
Sample |
% |
Sample |
% |
Sample |
% |
Sample |
% |
Sample |
% |
Total |
1 |
2.04 |
9 |
10.59 |
6 |
15.40 |
7 |
10.94 |
23 |
9.71 |
"Yes" to Period; 0 Days Reported |
1 |
2.04 |
0 |
0.00 |
6 |
15.40 |
3 |
4.69 |
10 |
4.22 |
"No" to Period; Greater Than 0 Days Reported |
N/A |
9 |
10.59 |
N/A |
4 |
6.25 |
13 |
5.49 | ||
Source: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment.
Exhibit 7.1.19 Past 12-Month Use of Alcohol: Percentage of Inconsistent Respondents | ||||||||||
Single Gate Questions |
Multiple Gate Questions |
|||||||||
Multiple Use Questions Absent |
Multiple Use Questions Present |
Multiple Use Questions Absent |
Multiple Use Questions Present |
Total ACASI | ||||||
Type of Inconsistency |
Sample |
% |
Sample |
% |
Sample |
% |
Sample |
% |
Sample |
% |
Total |
N/A |
30 |
9.35 |
N/A |
29 |
11.74 |
59 |
10.39 | ||
"Yes" to Period; 0 Days Reported |
N/A |
18 |
5.61 |
N/A |
20 |
8.10 |
38 |
6.69 | ||
"No" to Period; Greater Than 0 Days Reported |
N/A |
12 |
3.74 |
N/A |
9 |
3.64 |
21 |
3.70 | ||
Source: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment.
Exhibit 7.1.20 Past 12-Month Use of Marijuana: Percentage of Inconsistent Respondents | ||||||||||
Single Gate Questions |
Multiple Gate Questions |
|||||||||
Multiple Use Questions Absent |
Multiple Use Questions Present |
Multiple Use Questions Absent |
Multiple Use Questions Present |
Total ACASI | ||||||
Type of Inconsistency |
Sample |
% |
Sample |
% |
Sample |
% |
Sample |
% |
Sample |
% |
Total |
NA |
14 |
12.73 |
NA |
12 |
15.00 |
26 |
13.68 | ||
"Yes" to Period; 0 Days Reported |
NA |
3 |
2.73 |
NA |
6 |
7.50 |
9 |
4.74 | ||
"No" to Period; Greater Than 0 Days Reported |
NA |
11 |
10.00 |
NA |
6 |
7.50 |
17 |
8.95 | ||
Source: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment.
Exhibit 7.1.21 Average Time to Complete Treatment Sections, by Old and New Treatment Versions Single Gate Questions Multiple Gate Questions Questionnaire Section # of Cases Time # of Cases Time Tobacco 1,068 1.49 909 1.71 Alcohol 1,069 3.20 907 3.36 Marijuana 1,069 0.80 907 1.02 Cocaine 1,069 0.35 907 0.59 Crack 633 0.28 467 0.54 Heroin 1,069 0.19 907 0.39 Hallucinogens 1,068 1.48 907 1.42 Inhalants 1,066 2.44 906 2.41 Total for Treatment Sections 1,071 10.23 911 11.40 Source: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment.
Exhibit 7.1.22 Breakoff Rates, by Old and New Treatment Versions Single Gate Questions Multiple Gate Questions Cases Included n % n % Cases Ever Recorded as Breakoff Even if Completed Later 89 8.31 74 8.12 Cases Finalized as Breakoff 16 1.49 16 1.76 Total Number of Respondents Assigned to Treatment Versions 1,071 911 Source: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment.
Exhibit 7.1.23 Respondent Reactions to CAI Interview, by Old and New Treatment Versions Single Gate Questions Multiple Gate Questions Item n % n % How Difficult to Use Computer? Very difficult 22 2.08 20 2.23 Somewhat difficult 75 7.10 49 5.47 Not at all difficult 959 90.81 827 92.30 Total 1,056 100.00 896 100.00 Able to Enter Answers Easily? Yes 949 89.78 775 86.50 No 108 10.22 121 13.50 Total 1,057 100.00 896 100.00 Wanted to Change Previous Answer But Did Not? Yes 195 18.52 162 18.14 No 858 81.48 731 81.86 Total 1,053 100.00 893 100.00 Level of interest in interview Very boring 69 6.58 59 6.61 Somewhat boring 116 11.06 111 12.44 Neither boring nor interesting 283 26.98 224 25.11 Somewhat interesting 364 34.70 305 34.19 Very interesting 217 20.69 193 21.64 Total 1,049 100.0 892 100.00 Accuracy and Completeness of Answers Very accurate and complete 872 82.81 748 83.76 Fairly accurate and complete 171 16.24 133 14.89 Not very accurate and complete 10 0.95 12 1.34 Total 1,053 100.00 893 100.00 Source: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 7.2 Multiple Opportunities to Report Use The idea behind allowing respondents more than one opportunity to report drug use was that respondents who were initially unwilling to report more frequent use might change their minds and report the usage in a later question. Respondents who reported use in the past 12 months were given a second opportunity to report use in the past 30 days by being routed to the 30-day frequency question. Respondents who reported use more than 12 months ago (but within the past 3 years) were given the opportunity to report use in the past 12 months by being routed to the 12-month frequency question. Subsequently, respondents who indicated 12-month use were then also routed to the 30-day frequency item. Respondents who reported use more than 3 years ago were not included in any of the multiple use routing schemes. 7.2.1 Prevalence Estimates Exhibits 7.2.1 through 7.2.15 compare prevalence estimates between the two multiple use treatments for lifetime drug use, past 12-month use, and past 30-day use for cigarettes, alcohol, marijuana, cocaine, and any illicit drug use. In these exhibits, comparable data are included for the 1997 Quarter 4 PAPI data collection. The results do not show a consistent increase in drug use reporting for the inclusion of the multiple questioning approach. For drugs other than tobacco and alcohol, lifetime prevalence increased under the multiple use approach, but for 12-month and 30-day use, many of the drug prevalences appeared to decrease under the multiple questioning approach. Although sample sizes for some of the drugs were quite small and the associated prevalence estimates may be unstable, it seems that the multiple use approach may have introduced random variation (or "noise") into the data rather than reflect any true increase in reporting. It should be noted, however, that the prevalence estimates in the multiple questioning approach can be manipulated by the rules used to classify the recency of use. Rules must be defined to determine how to classify each respondent based on his or her recency of use. These rules can become quite complex, particularly when combined with the consistency check treatment. In some cases, a respondent may give highly inconsistent answers, and the ensuing prevalence estimates can be generated using either a very conservative or a very liberal (or anywhere in between) classification scheme. A conservative scheme would require a respondent's data to be entirely consistent before his or her data were included in the prevalence analysis. A liberal scheme would allow for a "preponderance of the evidence" rule, which would categorize the respondent based on what the majority of his or her data indicate. For the prevalence exhibits presented here, we have chosen to use a conservative classification scheme so that the prevalence estimates will be somewhat lower than would be obtained with a more liberal classification scheme. To illustrate how editing rules affect the results, we also created a series of weighted estimates using different editing rules. In Exhibit 7.2.16, we compare theestimates for 30-day use for youths and adults. These exhibits display the estimates using the raw variables, which make use of the most direct question on use during the 30-day period; a most liberal editing rule, which counts a person as a 30-day user if he or she gave any indication of use, that is, provided consistent reports of 30-day use, indicated that his or her most recent use was in the 30-day period but reported using 0 days in the past 30 days, or indicated that his or her most recent use was more than 30 days ago but reported using more than 0 days in the past 30 days; and an approximate NHSDA editing rule, which counted some inconsistent reporters as 30-day users. Under our edited variables, inconsistent 30-day users were only counted as 30-day users if they had not been consistent in reporting 12-month use. Examining the results, we note that using liberal editing rules leads to higher reports than using either the conservative editing rules we have used or the rule that is similar to the NHSDA, particularly for those treatments employing multiple use questions. Also, it is interesting to note that the most liberal editing rule tended to track the estimates from the raw variables. This is because the number of people who reported that they used in the past 30 days and who subsequently reported 0 days of use tended to be balanced by the number who said they did not use in the past 30 days and who subsequently reported some days of use.17 7.2.2 Inconsistencies in Reporting When examining the utility of the multiple questioning approach, it is useful to consider how many respondents reported more recent use as a result of being routed to a question that gave them an opportunity to do so. Exhibit 7.2.17 provides these data in two ways. It was possible that respondents could report more recent use when given a second chance to report, and there was also the possibility that respondents who initially reported 12-month or 30-day use might negate this answer as part of the multiple use questioning. For example, a respondent who reported use of marijuana during the past 12 months would then be routed to the series of questions on frequency of use in the past 12 months. This series of questions includes a response option for "no use during the past 12 months" (because some respondents would be routed to this question after reporting use more than 12 months ago but during the past 3 years). Ifthis respondent then selects the "no use" option, he or she is routed past the 12-month frequency question. So, the multiple use feature has the ability to create more recent users as well as to negate users. Both cases are observed in Exhibit 7.2.17. The data in this exhibit are quite interesting. A total of 141 respondents gave at least one inconsistent response as a result of the multiple use treatment. Based on an overall sample size of 1,025 respondents assigned to the multiple use treatment, this means approximately 14% of the sample was affected by the multiple use treatment. On average across the four multiple use treatments, approximately two thirds of these respondents indicated more recent use, while a third suggested their use was less recent. We also examined the inconsistencies in reporting 30-day use for alcohol, cigarettes, marijuana, hallucinogens, and inhalants by determining the proportion of consistent reporters among those who gave any indication of use in the past 30 days. We examined the PAPI data and the analysis was confined to data for the ACASI respondents in the multiple use treatment. There is only a slight indication that the ACASI respondents gave more consistent reports (data not shown in an exhibit). For alcohol, 85% of the respondents who gave any indication of use in the past 30 days were consistent reporters of use in the past 30 days for both the PAPI comparison group and the ACASI multiple use treatment group; for cigarettes, 86% of the PAPI respondents and 89% of the ACASI respondents were consistent reporters. For marijuana, the corresponding figures are 69% for the PAPI respondents and 82% for the ACASI respondents. For hallucinogens, only 37% and 38% of the respondents in PAPI and ACASI, respectively, gave consistent reports. For inhalants, among those who gave any indication of use in the past 30 days, 58% of the PAPI respondents and 43% of the ACASI respondents gave consistent reports. These large inconsistencies in reporting indicate that more work still needs to be done to increase the saliency of the reference periods for the respondents and to assist them in deciding when an event is in or out of the reference period. For rarely used drugs, some respondents may be reporting the total number of times that they have used the substance, not the number of times in the past 30 days. 7.2.3 Operational Aspects of Reporting Under Multiple Opportunities to Report Use Time required to complete the interview. Exhibit 7.2.18 provides descriptive data on the average length of time required to complete the treatment section of the 1997 field experiment instrument when the multiple use treatment was and was not in use. Data are included for each individual drug section and for the treatment section as a whole. From this exhibit, we see that the average time to complete each drug section was nearly identical between the two multiple use conditions. The overall average times were identical as well. It appears that the additional questions respondents must answer in the multiple use treatment have little, if any, affect on the overall length of theinterview. More detailed analysis of timing data from the field experiment are presented in Section 7.5. Breakoff rates. We next compared the rate of incomplete interviews (commonly known as "breakoffs") by analyzing whether the multiple use treatment was in use. Breakoff cases accounted for only a small number of the total number of interviews completed for the 1997 field experiment. However, if the multiple use treatment had caused respondents not to complete the full interview, we would view this as a serious drawback of the methodology. We analyzed the breakoff data in two ways. First, we compared the percentage of cases ever reported as a breakoff (even if the interviewer went on to finalize the case as a completed interview) by multiple use status. Then, we compared the percentage of finalized breakoff cases by multiple use status. Both sets of data are presented in Exhibit 7.2.19. The data show fundamentally that the multiple use treatment had no effect on the breakoff rate for the 1997 field experiment. Respondent reactions as reported in the debriefing questionnaire. Finally, we analyzed items from the respondent debriefing questions to see whether the multiple use treatment had any effect on respondent reactions to the CAI NHSDA interview. Exhibit 7.2.20 includes data from five items included in the respondent debriefing that we thought might vary by treatment version. Specifically, these items asked respondents to rate their difficulty in using the computer, their interest in the interview, and the accuracy and completeness of their answers. In addition, respondents were asked whether they were able to enter their answers easily and whether they wanted to change an answer to a previous question but did not. The data in Exhibit 7.2.20 show that the multiple use treatment had no effect on respondents' perceptions of the interview as measured by these five items.
Exhibit 7.2.1 Lifetime Use of Cigarettes, by Opportunities to Report Use Respondent Characteristics ACASI Treatment Groups Comparison Group Multiple Use Questions Absent Multiple Use Questions Present Total ACASI 1997 Treatment Version: 1, 3, 5, 7 2, 4, 6, 8 Total 73.87% 69.92% 71.96% 70.87% Age Group 12 to 17 47.37% 41.73% 44.48% 36.05% 18+ 76.77% 73.45% 75.18% 74.94% Gender Male 77.52% 70.61% 74.25% 74.74% Female 70.34% 69.29% 69.83% 67.25% Race/Ethnicity Hispanic 64.80% 62.62% 63.68% 55.82% Non-Hisp., Black 72.83% 54.21% 64.30% 61.62% Non-Hisp., All Other Races 74.81% 73.22% 74.04% 73.81% Education1 < High School 79.66% 76.50% 77.83% 70.28% High School 78.03% 81.71% 79.73% 76.65% > High School 75.27% 66.72% 71.35% 75.27% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.2.2 Lifetime Use of Alcohol, by Opportunities to Report Use Respondent Characteristics ACASI Treatment Groups Comparison Group Multiple Use Questions Absent Multiple Use Questions Present Total ACASI 1997 Treatment Version: 1, 3, 5, 7 2, 4, 6, 8 Total 83.53% 82.75% 83.16% 82.15% Age Group 12 to 17 46.93% 42.97% 44.90% 38.01% 18+ 87.53% 87.74% 87.63% 87.31% Gender Male 84.98% 82.81% 83.95% 87.07% Female 82.12% 82.70% 82.41% 77.55% Race/Ethnicity Hispanic 72.09% 76.34% 74.26% 69.45% Non-Hisp., Black 68.01% 62.61% 65.54% 72.35% Non-Hisp., All Other Races 87.35% 86.71% 87.04% 84.98% Education1 < High School 81.52% 82.86% 82.30% 77.22% High School 86.44% 82.74% 84.73% 85.83% > High School 89.65% 92.95% 91.16% 91.48% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.2.3 Lifetime Use of Marijuana, by Opportunities to Report Use Respondent Characteristics ACASI Treatment Groups Comparison Group Multiple Use Questions Absent Multiple Use Questions Present Total ACASI 1997 Treatment Version: 1, 3, 5, 7 2, 4, 6, 8 Total 33.38% 37.13% 35.18% 34.96% Age Group 12 to 17 21.79% 19.38% 20.56% 16.10% 18+ 34.64% 39.35% 36.90% 37.17% Gender Male 36.19% 39.56% 37.78% 40.79% Female 30.65% 34.93% 32.75% 29.51% Race/Ethnicity Hispanic 35.41% 42.55% 39.06% 24.59% Non-Hisp., Black 37.18% 23.57% 30.95% 31.43% Non-Hisp., All Other Races 32.50% 38.90% 35.60% 36.48% Education1 < High School 25.49% 29.56% 27.85% 32.84% High School 35.58% 36.62% 36.06% 36.60% > High School 36.14% 44.87% 40.15% 38.91% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.2.4 Lifetime Use of Cocaine, by Opportunities to Report Use Respondent Characteristics ACASI Treatment Groups Comparison Group Multiple Use Questions Absent Multiple Use Questions Present Total ACASI 1997 Treatment Version: 1, 3, 5, 7 2, 4, 6, 8 Total 12.11% 17.92% 14.91% 10.03% Age Group 12 to 17 2.74% 2.96% 2.86% 3.13% 18+ 13.13% 19.80% 16.32% 10.84% Gender Male 13.17% 24.65% 18.60% 12.47% Female 11.08% 11.86% 11.46% 7.76% Race/Ethnicity Hispanic 13.78% 20.67% 17.30% 7.32% Non-Hisp., Black 12.79% 6.48% 9.90% 7.57% Non-Hisp., All Other Races 11.84% 19.59% 15.59% 10.70% Education1 < High School 14.45% 31.82% 24.51% 9.52% High School 16.02% 12.25% 14.27% 10.37% > High School 10.91% 20.39% 15.26% 11.58% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.2.5 Lifetime Use of Any Illicit Drug, by Opportunities to Report Use Respondent Characteristics ACASI Treatment Groups Comparison Group Multiple Use Questions Absent Multiple Use Questions Present Total ACASI 1997 Treatment Version: 1, 3, 5, 7 2, 4, 6, 8 Total 41.59% 46.00% 43.72% 37.50% Age Group 12 to 17 32.80% 29.59% 31.15% 20.45% 18+ 42.56% 48.06% 45.19% 39.49% Gender Male 38.83% 49.18% 43.72% 43.44% Female 44.27% 43.14% 43.72% 31.94% Race/Ethnicity Hispanic 39.99% 48.32% 44.25% 28.63% Non-Hisp., Black 43.67% 28.22% 36.59% 33.40% Non-Hisp., All Other Races 41.34% 48.77% 44.93% 38.99% Education1 < High School 31.64% 54.79% 45.05% 37.22% High School 46.50% 44.04% 45.36% 38.42% > High School 42.47% 48.25% 45.12% 40.92% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.2.6 Past 12-Month Use of Cigarettes, by Opportunities to Report Use Respondent Characteristics ACASI Treatment Groups Comparison Group Multiple Use Questions Absent Multiple Use Questions Present Total ACASI 1997 Treatment Version: 1, 3, 5, 7 2, 4, 6, 8 Total 29.20% 33.32% 31.19% 33.52% Age Group 12 to 17 27.42% 18.55% 22.88% 25.18% 18+ 29.39% 35.17% 32.16% 34.49% Gender Male 34.81% 37.01% 35.85% 34.17% Female 23.77% 30.00% 26.82% 32.91% Race/Ethnicity Hispanic 34.22% 23.13% 28.55% 32.69% Non-Hisp., Black 41.84% 15.85% 29.94% 35.19% Non-Hisp., All Other Races 26.44% 37.18% 31.64% 33.29% Education1 < High School 35.70% 52.11% 45.20% 34.76% High School 26.67% 46.89% 36.04% 41.55% > High School 29.73% 20.88% 25.67% 29.70% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.2.7 Past 12-Month Use of Alcohol, by Opportunities to Report Use Respondent Characteristics ACASI Treatment Groups Comparison Group Multiple Use Questions Absent Multiple Use Questions Present Total ACASI 1997 Treatment Version: 1, 3, 5, 7 2, 4, 6, 8 Total 66.16% 70.56% 68.28% 64.95% Age Group 12 to 17 37.68% 35.28% 36.45% 32.74% 18+ 69.27% 74.98% 72.00% 68.71% Gender Male 63.43% 76.85% 69.78% 70.07% Female 68.80% 64.89% 66.88% 60.15% Race/Ethnicity Hispanic 60.90% 66.28% 63.65% 57.10% Non-Hisp., Black 54.92% 44.87% 50.31% 53.54% Non-Hisp., All Other Races 68.67% 75.26% 71.86% 67.64% Education1 < High School 35.59% 68.41% 54.60% 48.54% High School 70.92% 70.67% 70.80% 68.12% > High School 75.98% 80.37% 77.99% 75.47% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.2.8 Past 12-Month Use of Marijuana, by Opportunities to Report Use Respondent Characteristics ACASI Treatment Groups Comparison Group Multiple Use Questions Absent Multiple Use Questions Present Total ACASI 1997 Treatment Version: 1, 3, 5, 7 2, 4, 6, 8 Total 9.12% 11.45% 10.24% 9.36% Age Group 12 to 17 17.03% 16.36% 16.69% 12.97% 18+ 8.26% 10.83% 9.49% 8.94% Gender Male 11.33% 16.77% 13.91% 13.08% Female 6.98% 6.65% 6.82% 5.88% Race/Ethnicity Hispanic 15.05% 12.98% 13.99% 10.21% Non-Hisp., Black 8.94% 7.56% 8.31% 9.60% Non-Hisp., All Other Races 8.67% 11.96% 10.26% 9.25% Education1 < High School 8.69% 7.58% 8.05% 14.87% High School 6.95% 10.50% 8.59% 10.10% > High School 9.03% 12.28% 10.52% 6.30% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.2.9 Past 12-Month Use of Cocaine, by Opportunities to Report Use Respondent Characteristics ACASI Treatment Groups Comparison Group Multiple Use Questions Absent Multiple Use Questions Present Total ACASI 1997 Treatment Version: 1, 3, 5, 7 2, 4, 6, 8 Total 3.11% 2.12% 2.63% 1.60% Age Group 12 to 17 1.75% 1.79% 1.77% 2.54% 18+ 3.26% 2.16% 2.74% 1.49% Gender Male 3.17% 2.95% 3.07% 2.10% Female 3.06% 1.37% 2.23% 1.13% Race/Ethnicity Hispanic 4.18% 5.04% 4.62% 1.56% Non-Hisp., Black 4.86% 1.67% 3.40% 2.98% Non-Hisp., All Other Races 2.70% 1.93% 2.33% 1.36% Education1 < High School 8.90% 2.48% 5.19% 1.87% High School 1.51% 2.27% 1.86% 2.03% > High School 3.12% 1.97% 2.59% 1.01% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.2.10 Past 12-Month Use of Any Illicit Drug, by Opportunities to Report Use Respondent Characteristics ACASI Treatment Groups Comparison Group Multiple Use Questions Absent Multiple Use Questions Present Total ACASI 1997 Treatment Version: 1, 3, 5, 7 2, 4, 6, 8 Total 14.54% 15.82% 15.16% 10.28% Age Group 12 to 17 24.26% 21.87% 23.03% 14.54% 18+ 13.48% 15.06% 14.24% 9.78% Gender Male 13.08% 19.77% 16.24% 13.87% Female 15.96% 12.26% 14.14% 6.93% Race/Ethnicity Hispanic 20.34% 20.06% 20.20% 12.33% Non-Hisp., Black 14.42% 10.76% 12.74% 9.99% Non-Hisp., All Other Races 14.09% 16.28% 15.15% 10.16% Education1 < High School 13.76% 9.91% 11.53% 14.57% High School 14.73% 12.46% 13.68% 10.63% > High School 12.59% 18.75% 15.41% 7.71% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.2.11 Past 30-Day Use of Cigarettes, by Opportunities to Report Use Respondent Characteristics ACASI Treatment Groups Comparison Group Multiple Use Questions Absent Multiple Use Questions Present Total ACASI 1997 Treatment Version: 1, 3, 5, 7 2, 4, 6, 8 Total 21.75% 30.98% 26.20% 30.45% Age Group 12 to 17 17.31% 14.98% 16.11% 18.56% 18+ 22.23% 32.99% 27.38% 31.84% Gender Male 23.60% 33.82% 28.43% 31.10% Female 19.95% 28.43% 24.11% 29.84% Race/Ethnicity Hispanic 29.29% 21.55% 25.33% 28.86% Non-Hisp., Black 36.76% 10.63% 24.79% 33.03% Non-Hisp., All Other Races 18.34% 35.26% 26.53% 30.13% Education1 < High School 33.38% 51.74% 44.01% 34.23% High School 22.60% 43.42% 32.25% 38.72% > High School 19.41% 18.89% 19.17% 26.50% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.2.12 Past 30-Day Use of Alcohol, by Opportunities to Report Use Respondent Characteristics ACASI Treatment Groups Comparison Group Multiple Use Questions Absent Multiple Use Questions Present Total ACASI 1997 Treatment Version: 1, 3, 5, 7 2, 4, 6, 8 Total 50.23% 47.04% 48.70% 52.21% Age Group 12 to 17 18.07% 16.10% 17.06% 18.84% 18+ 53.75% 50.92% 52.40% 56.11% Gender Male 45.82% 56.81% 51.02% 60.23% Female 54.51% 38.24% 46.53% 44.70% Race/Ethnicity Hispanic 47.53% 28.58% 37.84% 40.79% Non-Hisp., Black 40.26% 29.24% 35.21% 41.19% Non-Hisp., All Other Races 52.31% 51.72% 52.02% 55.15% Education1 < High School 21.18% 37.88% 30.85% 40.55% High School 49.16% 45.90% 47.65% 55.62% > High School 64.33% 59.22% 61.99% 61.34% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.2.13 Past 30-Day Use of Marijuana, by Opportunities to Report Use Respondent Characteristics ACASI Treatment Groups Comparison Group Multiple Use Questions Absent Multiple Use Questions Present Total ACASI 1997 Treatment Version: 1, 3, 5, 7 2, 4, 6, 8 Total 5.35% 4.09% 4.74% 5.28% Age Group 12 to 17 9.77% 7.03% 8.37% 7.30% 18+ 4.86% 3.72% 4.32% 5.04% Gender Male 7.42% 6.55% 7.01% 7.30% Female 3.34% 1.88% 2.62% 3.39% Race/Ethnicity Hispanic 2.40% 5.11% 3.79% 4.48% Non-Hisp., Black 5.05% 3.93% 4.54% 6.05% Non-Hisp., All Other Races 5.65% 4.03% 4.86% 5.21% Education1 < High School 7.07% 3.58% 5.05% 10.13% High School 3.83% 4.64% 4.21% 5.92% > High School 5.04% 3.16% 4.18% 2.86% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.2.14 Past 30-Day Use of Cocaine, by Opportunities to Report Use Respondent Characteristics ACASI Treatment Groups Comparison Group Multiple Use Questions Absent Multiple Use Questions Present Total ACASI 1997 Treatment Version: 1, 3, 5, 7 2, 4, 6, 8 Total 0.56% 0.57% 0.57% 0.59% Age Group 12 to 17 0.21% 1.08% 0.66% 1.09% 18+ 0.60% 0.51% 0.56% 0.53% Gender Male 0.30% 0.58% 0.43% 0.61% Female 0.81% 0.57% 0.69% 0.56% Race/Ethnicity Hispanic 0.68% 2.09% 1.40% 0.80% Non-Hisp., Black 0.96% 1.12% 1.03% 2.09% Non-Hisp., All Other Races 0.48% 0.34% 0.41% 0.30% Education1 < High School 2.35% 1.14% 1.65% 0.87% High School 0.46% 0.91% 0.67% 0.89% > High School 0.29% 0.00% 0.16% 0.18% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.2.15 Past 30-Day Use of Any Illicit Drug, by Opportunities to Report Use Respondent Characteristics ACASI Treatment Groups Comparison Group Multiple Use Questions Absent Multiple Use Questions Present Total ACASI 1997 Treatment Version: 1, 3, 5, 7 2, 4, 6, 8 Total 6.65% 5.13% 5.91% 5.44% Age Group 12 to 17 13.10% 10.85% 11.95% 7.98% 18+ 5.94% 4.41% 5.21% 5.14% Gender Male 8.66% 7.58% 8.15% 7.68% Female 4.70% 2.91% 3.82% 3.34% Race/Ethnicity Hispanic 3.64% 6.34% 5.02% 4.60% Non-Hisp., Black 7.15% 6.30% 6.76% 6.45% Non-Hisp., All Other Races 6.80% 4.82% 5.84% 5.33% Education1 < High School 7.59% 5.33% 6.28% 9.46% High School 5.16% 5.01% 5.09% 5.94% > High School 6.08% 3.66% 4.97% 3.25% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.2.16 Comparison of 30-Day User Coding Schemes Drugs of Interest Single Gate Questions Multiple Gate Questions PAPI Raw Most Approximate Edited Raw Most Approximate Edited Alcohol Total 50.70% 49.87% 47.64% 47.35% 55.16% 55.78% 51.78% 50.27% 46.45% 12 to 17 20.78% 21.49% 18.79% 17.43% 21.04% 21.36% 18.70% 16.60% 12.04% 18+ 54.28% 53.26% 51.09% 50.93% 59.05% 59.70% 55.55% 54.11% 50.47% Cigarettes Total 26.19% 26.67% 26.61% 26.61% 27.22% 26.63% 25.73% 25.73% 27.47% 12 to 17 16.41% 16.92% 16.65% 16.62% 20.30% 16.97% 15.49% 15.49% 12.83% 18+ 27.36% 27.84% 27.80% 27.80% 28.01% 27.73% 26.89% 26.89% 29.19% Marijuana Total 6.18% 6.47% 6.45% 5.54% 4.68% 4.67% 3.92% 3.82% 4.24% 12 to 17 9.44% 9.85% 9.73% 9.39% 8.63% 8.76% 7.63% 7.12% 5.26% 18+ 5.79% 6.06% 6.06% 5.08% 4.23% 4.20% 3.50% 3.44% 4.12% Cocaine Total 0.61% 0.61% 0.60% 0.60% 0.84% 0.58% 0.53% 0.53% 0.30% 12 to 17 1.02% 1.02% 0.98% 0.98% 0.64% 0.49% 0.26% 0.26% 0.71% 18+ 0.56% 0.56% 0.56% 0.56% 0.86% 0.59% 0.56% 0.56% 0.26% Any Illicit Drug1 Total 7.82% 7.79% 6.91% 5.62% 4.89% 4.75% 5.44% 12 to 17 14.30% 13.95% 13.02% 12.15% 11.52% 10.63% 7.98% 18+ 7.05% 7.05% 6.18% 4.87% 4.30% 4.08% 5.14% Alcohol Total 52.58% 52.58% 50.23% 50.23% 52.96% 52.61% 48.82% 47.04% 46.45% 12 to 17 21.50% 21.50% 18.07% 18.07% 20.32% 21.38% 19.40% 16.10% 12.04% 18+ 55.97% 55.97% 53.75% 53.75% 57.05% 56.53% 52.50% 50.92% 50.47% Cigarettes Total 22.52% 22.32% 21.75% 21.75% 31.13% 31.31% 30.99% 30.98% 27.47% 12 to 17 19.54% 17.82% 17.31% 17.31% 16.84% 16.11% 15.01% 14.98% 12.83% 18+ 22.84% 22.81% 22.23% 22.23% 32.92% 33.21% 32.99% 32.99% 29.19% Marijuana Total 5.97% 5.97% 5.35% 5.35% 4.97% 5.28% 5.22% 4.09% 4.24% 12 to 17 10.34% 10.34% 9.77% 9.77% 7.87% 8.42% 7.84% 7.03% 5.26% 18+ 5.49% 5.49% 4.86% 4.86% 4.61% 4.89% 4.89% 3.72% 4.12% Cocaine Total 0.56% 0.56% 0.56% 0.56% 0.87% 0.63% 0.57% 0.57% 0.30% 12 to 17 0.21% 0.21% 0.21% 0.21% 1.46% 1.32% 1.08% 1.08% 0.71% 18+ 0.60% 0.60% 0.60% 0.60% 0.80% 0.54% 0.51% 0.51% 0.26% Any Illicit Drug 1 Total 7.31% 6.65% 6.65% 6.27% 6.24% 5.13% 5.44% 12 to 17 14.04% 13.10% 13.10% 12.65% 12.62% 10.85% 7.98% 18+ 6.57% 5.94% 5.94% 5.47% 5.44% 4.41% 5.14% Alcohol Total 51.09% 49.91% 45.37% 44.80% 54.59% 55.55% 54.15% 52.98% 46.45% 12 to 17 20.30% 20.91% 17.92% 16.16% 21.59% 22.05% 19.72% 18.12% 12.04% 18+ 54.82% 53.42% 48.69% 48.27% 58.30% 59.32% 58.02% 56.91% 50.47% Cigarettes Total 23.13% 22.87% 22.87% 22.87% 30.56% 30.80% 29.86% 29.86% 27.47% 12 to 17 16.52% 15.50% 15.50% 15.50% 20.08% 18.63% 16.87% 16.83% 12.83% 18+ 23.93% 23.76% 23.76% 23.76% 31.74% 32.17% 31.33% 31.33% 29.19% Marijuana Total 5.10% 4.56% 3.95% 3.74% 5.91% 6.82% 6.75% 5.84% 4.24% 12 to 17 8.46% 8.70% 8.22% 7.73% 9.80% 10.12% 9.44% 9.11% 5.26% 18+ 4.70% 4.06% 3.43% 3.26% 5.48% 6.45% 6.45% 5.48% 4.12% Cocaine Total 0.70% 0.62% 0.59% 0.59% 0.72% 0.57% 0.54% 0.54% 0.30% 12 to 17 1.03% 1.03% 1.03% 1.03% 0.64% 0.49% 0.22% 0.22% 0.71% 18+ 0.66% 0.57% 0.54% 0.54% 0.73% 0.57% 0.57% 0.57% 0.26% Any Illicit Drug 1 Total 5.47% 4.83% 4.66% 8.27% 8.23% 7.30% 5.44% 12 to 17 12.18% 11.67% 10.44% 14.67% 14.26% 13.71% 7.98% 18+ 4.66% 4.00% 3.96% 7.55% 7.55% 6.58% 5.14% Note: Raw variable estimates are unavailable for coding schemes for any illicit drug use. 1 Any illicit drug includes marijuana, cocaine, crack, heroin, inhalants, hallucinogens, and nonmedical use of analgesics, sedatives, stimulants, and tranquilizers. Source: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures, 1997 Field Experiment.
Exhibit 7.2.17 Number of Respondents Who Provided Inconsistent Reports of the Recency of Use as a Result of the Multiple Use Treatment Multiple Use Present Single Gate Question Multiple Gate Questions Consistency Checks Consistency Checks Absent Present Absent Present 2 4 6 8 Total Number of Respondents 285 264 219 207 975 Total Number of Inconsistencies 48 24 41 28 141 Suggests More Recent Use 38 16 22 17 93 Percentage of Inconsistencies 79.2 66.7 53.7 60.7 66.0 Suggests Less Recent Use 10 8 19 11 48 Percentage of Inconsistencies 20.8 33.3 46.3 39.3 34.0 Source: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment.
Exhibit 7.2.18 Average Time to Complete Treatment Sections, by Whether Multiple Use Was Present Average Time to Complete Multiple Use Present Multiple Use Absent Questionnaire Section # of Cases Time # of Cases Time Tobacco 1,022 1.6 955 1.6 Alcohol 1,020 3.3 956 3.3 Marijuana 1,020 0.9 956 0.9 Cocaine 1,020 0.5 956 0.5 Crack 1,020 0.4 80 0.6 Heroin 1,020 0.3 956 0.3 Hallucinogens 1,019 1.5 956 1.4 Inhalants 1,019 2.5 953 2.4 Total for Treatment Sections 1,022 10.9 956 10.5 Source: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment.
Exhibit 7.2.19 Breakoff Rates, by Multiple Use Status Breakoff Rate Multiple Use Present Multiple Use Absent Cases Included n % n % Cases Ever Recorded as Breakoff Even if Completed Later 85 8.3 78 8.2 Cases Finalized as Breakoff 17 1.7 15 1.6 Total Number of Respondents Assigned to Multiple Use Treatment 1,025 957 Source: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment.
Exhibit 7.2.20 Respondent Reactions to CAI Interview, by Multiple Use Status Multiple Use Status Multiple Use Present Multiple Use Absent Item n % n % How Difficult to Use Computer? Very difficult 23 2.3 19 2.0 Somewhat difficult 63 6.2 61 6.5 Not at all difficult 923 91.5 863 91.5 Total 1,009 100.0 943 100.0 Able to Enter Answers Easily? Yes 891 88.2 833 88.3 No 119 11.8 110 11.7 Total 1,010 100.0 943 100.0 Wanted to Change Previous Answer But Did Not? Yes 183 18.2 174 18.5 No 821 81.8 768 81.5 Total 1,004 100.0 942 100.0 Level of Interest in Interview Very boring 62 6.2 66 7.0 Somewhat boring 120 12.0 107 11.4 Neither boring nor interesting 259 25.8 248 26.4 Somewhat interesting 350 34.9 319 34.0 Very interesting 211 21.1 199 21.2 Total 1,003 100.0 939 100.0 Accuracy and Completeness of Answers Very accurate and complete 831 82.6 789 83.9 Fairly accurate and complete 163 16.2 141 15.0 Not very accurate and complete 12 1.2 10 1.1 Total 1,006 100.0 940 100.0 Source: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 7.3 Implementation of Consistency Checks by Respondents The consistency checks programmed for the consistency check treatment can be divided into two types. First, there are true inconsistencies, in which a respondent's answers to each of two questions cannot both be true. For example, a respondent who has reported her current age as 22 cannot logically report her first use of marijuana at age 35. Similarly, a respondent who reports drinking alcohol on 22 days during the past 30 days cannot logically report drinking alcohol on 3 days in the past 12 months. A second type of check that was programmed can be considered a verify check as opposed to a true inconsistency. In these cases, a respondent's answer is not technically inconsistent with previous information reported but rather is simply "unusual" given what we have learned from the data collected in previous NHSDAs. The two verify checks included in the 1997 field experiment prompted respondents to verify the accuracy of their response when they indicated an age at first use as equal to their current age or an age at first use less than 10. When discussing the outcome of the consistency check treatment, we first must consider the two types of consistency checks separately because they may reflect different effects on data quality. 7.3.1 Inconsistencies in the Final Unedited Respondent Data, by Presence or Absence of Consistency Checks Exhibit 7.3.1 shows the number of respondents in each of the four versions in which consistency checks were present who triggered at least one consistency check during the course of the interview. From this exhibit, we see that approximately 28% of the respondents assigned to receive consistency checks triggered at least one check item. Of those respondents, just over half (55%) triggered a verify check as opposed to a true inconsistency item. More respondents triggered a true consistency check in Treatments 4 and 8. This may be the result of additional confusion created by the multiple use treatment. However, it may only reflect the fact that there were more consistency checks programmed into these two treatments. Interestingly, the number of respondents who triggered verify items was higher for the two treatments that used the single gate question. Exhibit 7.3.2 shows a breakdown of the age of respondents who triggered at least one true inconsistency. Across all treatments, youths aged 12 to 17 were more likely to trigger a true inconsistency than adults aged 18 or older. In Treatment 8, the difference was especially pronounced: 23% of youths triggered an inconsistency and only 11.7% of adults did. In addition to determining the number of respondents who triggered any of the inconsistency items, we also wanted to calculate the total number of consistency checks triggered overall and by treatment. Exhibit 7.3.3 shows these data. Combining these data with data from Exhibit 7.3.1 shows that the average number of true consistency checks triggered was approximately 1.2 per respondent. The average number of verify checks triggered was approximately 1.2 per respondent as well. Of particular interest is whether the data coming out of the consistency checks were "cleaner" than the data going in. For the 1997 field experiment, we decided to route respondents through each consistency check only once. Thus, if a respondent reported her current age as 26 and her age at first use of cocaine as age 33, she was routed into a consistency check. If she chose to change her age at first use response to 30, her answers would still be inconsistent. However, the program was not designed to route respondents back through a consistency check a second time. We were concerned that multiple passes through a single consistency check might be overly burdensome to respondents. Exhibit 7.3.4 provides data on the consistency of responses following a consistency check. Each resolution process was examined and classified into one of four types. First, the data could be classified as consistent; that is, after being notified of the inconsistency, the respondent revised one or both of his or her answers so that the answers did not conflict with each other. Second, the data could remain inconsistent; even after changing one or both of the answers, the respondent's answers still conflicted with one another. Some responses were classified as "indeterminate" because the nature of the resolution process did not require the respondent to fully resolve the inconsistency. For example, in Treatment 8, a respondent may have reported that he used marijuana during the past 30 days; when asked the 30-day frequency item, however, he reported 0 days. He was then routed to a resolution screen that asked him to verify that he did not use marijuana in the past 30 days. If he indicated this was correct, that was the end of the resolution process, even though he was never presented with the two conflicting items. Although it seems safe to consider this respondent a nonuser for the 30-day period, for the sake of clarity we have classified these cases separately in Exhibit 7.3.4. Finally, in a small number of situations, the respondent recorded a "don't know" or "refused" response when presented with the resolution screen. In these situations, the program routed the respondent out of the resolution series; thus, the case cannot be classified into any of the other three categories. From Exhibit 7.3.4, we see that 30% of all inconsistencies were resolved as consistent, 17% were still inconsistent after the resolution process, and just over half (51%) the respondent confirmed an answer. If we assume that the confirmed answer is accurate, then the quality of 81% of the inconsistent responses was improved through the resolution process. Also from Exhibit 7.3.4, we find that slightly less than half of the inconsistencies resolved in Treatments 3 and 4 were determined to be consistent. In contrast, less than 20% of the inconsistencies resolved in Treatments 7 and 8 were determined to be consistent. The reason for this difference is not clear because the resolution questions do not vary significantly between the two contingent questioning structures. We hypothesized that respondents who were overly confused by the resolution process would enter a "don't know" or "refused" response as a method of avoiding the resolution task. We found only a small number of inconsistencies were "resolved" bythe respondent in this manner (a total of four resolutions across all treatment versions). We take this as a positive sign that the resolution process was not overly confusing for respondents and believe that, overall, the improvement in data consistency is an improvement to the overall quality of the NHSDA data as well. We also examined the resolution of the verify questions on age at first use in more detail. The results of this analysis are shown in Exhibit 7.3.5, which displays the number of respondents for the various drugs who reported very low ages at first use and the percentage who changed their answers as a result of the consistency check. Overall, 98 respondents gave ages at first use younger than 10 years old, and about 23% of these respondents indicated that this was an incorrect answer. Most of these respondents gave a new age that was consistent; however, a few did not complete the task, and we were left with the knowledge only that they had indicated that the very low age at first use was incorrect. Exhibit 7.3.5 also shows data on those whose reported age at first use was equal to their current age. The vast majority of these respondents confirmed that this was indeed their age at first use; however, about 6% gave a revised age at first use. 7.3.2 Effect of Revised Answers on Prevalence Estimates Based on the data presented in Section 7.3.1, it appears that the consistency check process is helpful in improving the consistency of the NHSDA data. In addition, the process seems relatively burden-free because less than a third of the respondents actually triggered a resolution screen and the average number of resolution screens triggered was quite low (1.2 for both the verify and the true inconsistency screens). Of equal importance, however, is the effect of the inconsistency resolution process on the prevalence estimates. Exhibits 7.3.6 through 7.3.20 compare prevalence estimates between the two levels of the consistency check treatment. In these exhibits, comparable data are included for the 1997 Quarter 4 PAPI data collection. The results show a fairly consistent increase in the drug prevalence rates for both lifetime and 12-month use. The 30-day rates are less consistent, but due to the small sample sizes for many of the drugs, these rates are also likely to be less reliable. The resolution process appears to have had a slight decreasing effect on the reports of youths aged 12 to 17, while the prevalence rates for adults aged 18 or older were increased by the presence of the resolution treatment. A large increase in the prevalence rates was also found for adults with less than a high school education when the consistency check treatment was included. 7.3.3 Operational Aspects of Reporting When Consistency Checks Are Used Time required to complete the interview. Exhibit 7.3.21 provides descriptive dataon the average length of time required to complete the treatment section of the instrument when consistency checks were and were not in use. Data are included for each individual drug section and for the treatment section as a whole. From this exhibit, we see that the average time to complete each drug section was nearly identical between the two resolution conditions. The overall average times were identical as well. However, the majority of respondents did not trigger many, if any, consistency checks during their interviews. To present a more realistic picture of the time added by the inclusion of resolution items, we compared the time to complete the treatment section by whether even one inconsistency was resolved during the respondent's interview. The results are presented in Exhibit 7.3.22. Here we see an increase of approximately 3 minutes when at least one consistency check was triggered compared to when none was triggered. One additional method for considering the time added when the consistency checks were present is to compare the time to complete a specific section of the instrument by whether an inconsistency was detected in that section. These data are presented in Exhibit 7.3.23. In some cases, sample sizes are quite small. However, we see that for many of the drug sections, triggering a consistency check could result in a doubling of the time to complete the section compared to when no consistency checks were triggered. More detailed analysis of the timing data from the 1997 field experiment are presented in Section 7.5. Breakoff rates. We next compared the rate of breakoffs by analyzing whether the multiple use treatment was in use. Breakoff cases accounted for only a small number of the total number of interviews. However, if the consistency checks had caused respondents not to complete the full interview, we would view this as a serious drawback of the methodology. We analyzed the breakoff data in two ways. First, we compared the percentage of cases ever reported as a breakoff (even if the interviewer went on to finalize the case as a completed interview) by the presence of consistency checks. Then, we compared the percentage of finalized breakoff cases. Both sets of data are presented in Exhibit 7.3.24. The data show fundamentally that the presence of consistency checks had no effect on the breakoff rate. Respondent reactions as reported in the debriefing questionnaire. We analyzed items from the respondent debriefing questions to see whether the consistency checks had any effect on respondent reactions to the CAI NHSDA interview. Exhibit 7.3.25 includes data from five items included in the respondent debriefing that we thought might vary by treatment version. Specifically, these items asked respondents to rate their difficulty in using the computer, their interest in the interview, and the accuracy and completeness of their answers. In addition, respondents were asked whether they were able to enter their answers easily and whether they wanted to change an answer to a previous question but did not. The data in Exhibit 6.3.51 show that respondents in the consistency check present group were slightly more likely than respondents who did not resolve inconsistencies to report that they were able to easily enter their answers into the computer (90.0% vs. 86.6%) and that the answers they gave were very accurate and complete (84.4% vs. 82.1%). For the other items included in Exhibit 7.3.25, no differences were found between the twogroups. Interviewer reports of respondent difficulties. Interviewers completed debriefing questions at the conclusion of each interview. For respondents who triggered at least one inconsistency item (a true inconsistency rather than only a verify item), one of these debriefing items asked the interviewer to explain why the respondent might have provided inconsistent data. A review of the open-ended responses indicates that the most common reason provided by the interviewers was the number of distractions during the interview. These distractions included the presence of young children, the presence of other adults, the telephone ringing, the doorbell ringing, and the television playing. Other explanations mentioned by the interviewers included respondent boredom, literacy problems, respondent fatigue, and respondents who simply were not paying close attention to what they were doing. Exhibit 7.3.26 includes data from several other interviewer debriefing items that we thought might differ based on whether the respondent was assigned to receive consistency checks. For the most part, interviewer reports were similar across the two modes. However, interviewers reported that slightly more respondents in the consistency check present group had no difficulty understanding the interview (84.4% vs. 81.4%) and were very interested in the ACASI interview (62.7% vs. 59.9%). Interviewers also reported that for slightly more of the respondents who did not receive the consistency checks, the audio component of ACASI was unnecessary (36.8% vs. 34.5%).
Exhibit 7.3.1 Number and Percentage of Respondents Who Triggered at Least One Consistency Check Consistency Checks Present Single Gate Question Multiple Gate Questions Multiple Use Questions Multiple Use Questions Absent Present Absent Present Treatment Version 3 4 7 8 Total Number of Respondents 285 264 219 207 975 Total Number of Respondents Who Triggered a Consistency Check 75 82 52 68 277 Percentage of Respondents 26.3 31.1 23.7 32.9 28.4 True Inconsistency 27 39 21 37 124 Percentage of Respondents 9.5 14.8 9.6 17.9 12.7 Percentage of Consistency Checks 36.0 47.6 40.3 54.4 44.8 Verify Only 48 43 31 31 153 Percentage of Respondents 16.8 16.3 14.2 15.0 15.7 Percentage of Consistency Checks 64.0 52.4 59.6 45.6 55.2 Source: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment.
Exhibit 7.3.2 Number of Respondents Who Triggered at Least One True Inconsistency, by Age and Treatment Consistency Checks Present Single Gate Question Multiple Gate Questions Multiple Use Questions Multiple Use Questions Absent Present Absent Present Treatment Version 3 4 7 8 Total Number of Respondents 285 264 219 207 975 Total Number of True Inconsistencies Triggered 27 39 21 37 124 Percentage of Respondents 9.5 14.8 9.6 17.9 12.7 12 to 17 Number of Respondents 157 148 118 113 536 Number Triggering True
Inconsistencies 16 22 11 26 75 Percentage of Respondents 10.2 14.9 9.3 23.0 14.0 18+ Number of Respondents 128 116 101 94 439 Number Triggering True
Inconsistencies 11 17 10 11 49 Percentage of Respondents 8.6 14.7 9.9 11.7 11.2 Source: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment.
Exhibit 7.3.3 Number of Consistency Checks Triggered, by Treatment Consistency Checks Present Single Gate Question Multiple Gate Questions Multiple Use Questions Multiple Use Questions Absent Present Absent Present Treatment Version 3 4 7 8 Total Number of Respondents 285 264 219 207 975 Total Number of Consistency Checks Triggered 95 101 60 83 339 True Inconsistency 31 50 24 45 150 Verify Only 64 51 36 38 189 Source: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment.
Exhibit 7.3.4 Data Consistency Following the Resolution Process Consistency Checks Present Single Gate Question Multiple Gate Questions Multiple Use Questions Multiple Use Questions Absent Present Absent Present Treatment Version 3 4 7 8 Total Number of Respondents 285 264 219 207 975 Total Number of True Inconsistencies Triggered 31 50 24 45 150 Made Change: Data Consistent 15 21 4 5 45 Percentage of inconsistencies 48.4 42.0 16.7 11.1 30.0 Made Change: Data Inconsistent 5 6 7 7 25 Percentage of inconsistencies 16.1 12.0 29.1 15.6 16.7 Confirmed Last Answer 8 23 13 32 76 Percentage of inconsistencies 25.8 46.0 54.2 71.1 50.7 Don't Know/Refused 3 0 0 1 4 Percentage of inconsistencies 9.7 - - 2.2 2.7 Source: National Household Survey on Drug Abuse: Development of Computer Assisted Interviewing Procedures; 1997 Field Experiment.
Exhibit 7.3.5 Summary of Consistency Resolution for Checks on Age at First Use Drug Very Low Age at First Use Reported Very Low Age at First Use Changed Reported Age Current Age Cigarettes Number 30 7 17 3 Percentage 23.33 17.65 Alcohol Number 50 7 29 0 Percentage 14.00 0.00 Marijuana Number 4 1 18 0 Percentage 25.00 0.00 Cocaine Number 1 1 5 0 Percentage 100.00 0.00 Crack Number 1 0 2 0 Percentage 0.00 0.00 Heroin Number 2 1 2 0 Percentage 50.00 0.00 Hallucinogens Number 3 2 11 1 Percentage 66.67 9.09 Inhalants Number 7 4 4 1 Percentage 57.14 25.00 Overall Drugs Number 98 23 88 5 Percentage 23.47 5.68 Source: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment.
Exhibit 7.3.6 Lifetime Use of Cigarettes, by Presence of Consistency Checks Respondent Characteristics ACASI Treatment Groups Comparison Group Consistency Checks Absent Consistency Checks Present Total ACASI 1997 Treatment Version: 1, 2, 5, 6 3, 4, 7, 8 Total 69.70% 74.45% 71.96% 70.87% Age Group 12 to 17 45.49% 43.29% 44.48% 36.05% 18+ 72.63% 77.96% 75.18% 74.94% Gender Male 75.47% 72.81% 74.25% 74.74% Female 63.97% 75.88% 69.83% 67.25% Race/Ethnicity Hispanic 61.10% 66.72% 63.68% 55.82% Non-Hisp., Black 63.99% 64.56% 64.30% 61.62% Non-Hisp., All Other Races 71.32% 77.15% 74.04% 73.81% Education1 < High School 69.58% 87.21% 77.83% 70.28% High School 74.28% 86.76% 79.73% 76.65% > High School 72.36% 70.37% 71.35% 75.27% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.3.7 Lifetime Use of Alcohol, by Presence of Consistency Checks Respondent Characteristics ACASI Treatment Groups Comparison Group Consistency Checks Absent Consistency Checks Present Total ACASI 1997 Treatment Version: 1, 2, 5, 6 3, 4, 7, 8 Total 82.12% 84.30% 83.16% 82.15% Age Group 12 to 17 45.55% 44.14% 44.90% 38.01% 18+ 86.54% 88.82% 87.63% 87.31% Gender Male 80.29% 88.26% 83.95% 87.07% Female 83.94% 80.83% 82.41% 77.55% Race/Ethnicity Hispanic 76.29% 71.87% 74.26% 69.45% Non-Hisp., Black 61.36% 69.05% 65.54% 72.35% Non-Hisp., All Other Races 85.77% 88.50% 87.04% 84.98% Education1 < High School 82.62% 81.94% 82.30% 77.22% High School 82.80% 87.21% 84.73% 85.83% > High School 90.68% 91.63% 91.16% 91.48% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.3.8 Lifetime Use of Marijuana, by Presence of Consistency Checks Respondent Characteristics ACASI Treatment Groups Comparison Group Consistency Checks Absent Consistency Checks Present Total ACASI 1997 Treatment Version: 1, 2, 5, 6 3, 4, 7, 8 Total 35.04% 35.34% 35.18% 34.96% Age Group 12 to 17 20.73% 20.36% 20.56% 16.10% 18+ 36.78% 37.02% 36.90% 37.17% Gender Male 37.89% 37.66% 37.78% 40.79% Female 32.22% 33.30% 32.75% 29.51% Race/Ethnicity Hispanic 49.07% 27.31% 39.06% 24.59% Non-Hisp., Black 26.19% 34.95% 30.95% 31.43% Non-Hisp., All Other Races 35.15% 36.10% 35.60% 36.48% Education1 < High School 30.04% 25.36% 27.85% 32.84% High School 35.73% 36.49% 36.06% 36.60% > High School 39.76% 40.52% 40.15% 38.91% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.3.9 Lifetime Use of Cocaine, by Presence of Consistency Checks Respondent Characteristics ACASI Treatment Groups Comparison Group Consistency Checks Absent Consistency Checks Present Total ACASI 1997 Treatment Version: 1, 2, 5, 6 3, 4, 7, 8 Total 11.61% 18.54% 14.91% 10.03% Age Group 12 to 17 2.46% 3.32% 2.86% 3.13% 18+ 12.72% 20.25% 16.32% 10.84% Gender Male 13.36% 24.76% 18.60% 12.47% Female 9.88% 13.10% 11.46% 7.76% Race/Ethnicity Hispanic 25.35% 7.86% 17.30% 7.32% Non-Hisp., Black 5.46% 13.65% 9.90% 7.57% Non-Hisp., All Other Races 11.34% 20.46% 15.59% 10.70% Education1 < High School 16.48% 33.64% 24.51% 9.52% High School 12.61% 16.41% 14.27% 10.37% > High School 11.59% 18.79% 15.26% 11.58% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.3.10 Lifetime Use of Any Illicit Drug, by Presence of Consistency Checks Respondent Characteristics ACASI Treatment Groups Comparison Group Consistency Checks Absent Consistency Checks Present Total ACASI 1997 Treatment Version: 1, 2, 5, 6 3, 4, 7, 8 Total 43.43% 44.03% 43.72% 37.50% Age Group 12 to 17 30.82% 31.55% 31.15% 20.45% 18+ 44.96% 45.44% 45.19% 39.49% Gender Male 40.18% 47.88% 43.72% 43.44% Female 46.66% 40.67% 43.72% 31.94% Race/Ethnicity Hispanic 51.88% 35.29% 44.25% 28.63% Non-Hisp., Black 28.87% 43.09% 36.59% 33.40% Non-Hisp., All Other Races 44.90% 44.98% 44.93% 38.99% Education1 < High School 36.28% 55.02% 45.05% 37.22% High School 50.83% 38.32% 45.36% 38.42% > High School 43.27% 46.91% 45.12% 40.92% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.3.11 Past 12-Month Use of Cigarettes, by Presence of Consistency Checks Respondent Characteristics ACASI Treatment Groups Comparison Group Consistency Checks Absent Consistency Checks Present Total ACASI 1997 Treatment Version: 1, 2, 5, 6 3, 4, 7, 8 Total 28.56% 34.07% 31.19% 33.52% Age Group 12 to 17 23.82% 21.77% 22.88% 25.18% 18+ 29.13% 35.46% 32.16% 34.49% Gender Male 37.26% 34.20% 35.85% 34.17% Female 19.92% 33.96% 26.82% 32.91% Race/Ethnicity Hispanic 23.36% 34.64% 28.55% 32.69% Non-Hisp., Black 23.36% 35.48% 29.94% 35.19% Non-Hisp., All Other Races 29.80% 33.73% 31.64% 33.29% Education1 < High School 34.32% 57.58% 45.20% 34.76% High School 32.47% 40.65% 36.04% 41.55% > High School 24.90% 26.42% 25.67% 29.70% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.3.12 Past 12-Month Use of Alcohol, by Presence of Consistency Checks Respondent Characteristics ACASI Treatment Groups Comparison Group Consistency Checks Absent Consistency Checks Present Total ACASI 1997 Treatment Version: 1, 2, 5, 6 3, 4, 7, 8 Total 65.09% 71.79% 68.28% 64.95% Age Group 12 to 17 36.99% 35.83% 36.45% 32.74% 18+ 68.49% 75.83% 72.00% 68.71% Gender Male 65.13% 75.23% 69.78% 70.07% Female 65.05% 68.77% 66.88% 60.15% Race/Ethnicity Hispanic 65.08% 61.97% 63.65% 57.10% Non-Hisp., Black 45.75% 54.16% 50.31% 53.54% Non-Hisp., All Other Races 68.02% 76.26% 71.86% 67.64% Education1 < High School 51.86% 57.71% 54.60% 48.54% High School 67.24% 75.38% 70.80% 68.12% > High School 74.81% 81.06% 77.99% 75.47% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.3.13 Past 12-Month Use of Marijuana, by Presence of Consistency Checks Respondent Characteristics ACASI Treatment Groups Comparison Group Consistency Checks Absent Consistency Checks Present Total ACASI 1997 Treatment Version: 1, 2, 5, 6 3, 4, 7, 8 Total 9.95% 10.56% 10.24% 9.36% Age Group 12 to 17 16.17% 17.29% 16.69% 12.97% 18+ 9.20% 9.80% 9.49% 8.94% Gender Male 13.43% 14.46% 13.91% 13.08% Female 6.50% 7.15% 6.82% 5.88% Race/Ethnicity Hispanic 20.85% 5.95% 13.99% 10.21% Non-Hisp., Black 7.41% 9.06% 8.31% 9.60% Non-Hisp., All Other Races 9.38% 11.27% 10.26% 9.25% Education1 < High School 9.98% 5.85% 8.05% 14.87% High School 8.81% 8.31% 8.59% 10.10% > High School 9.25% 11.75% 10.52% 6.30% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.3.14 Past 12-Month Use of Cocaine, by Presence of Consistency Checks Respondent Characteristics ACASI Treatment Groups Comparison Group Consistency Checks Absent Consistency Checks Present Total ACASI 1997 Treatment Version: 1, 2, 5, 6 3, 4, 7, 8 Total 2.28% 3.03% 2.63% 1.60% Age Group 12 to 17 1.74% 1.81% 1.77% 2.54% 18+ 2.34% 3.17% 2.74% 1.49% Gender Male 2.42% 3.82% 3.07% 2.10% Female 2.13% 2.34% 2.23% 1.13% Race/Ethnicity Hispanic 5.52% 3.56% 4.62% 1.56% Non-Hisp., Black 1.48% 5.02% 3.40% 2.98% Non-Hisp., All Other Races 2.11% 2.57% 2.33% 1.36% Education1 < High School 5.07% 5.32% 5.19% 1.87% High School 1.72% 2.04% 1.86% 2.03% > High School 1.94% 3.22% 2.59% 1.01% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4. .
Exhibit 7.3.15 Past 12-Month Use of Any Illicit Drug, by Presence of Consistency Checks Respondent Characteristics ACASI Treatment Groups Comparison Group Consistency Checks Absent Consistency Checks Present Total ACASI 1997 Treatment Version: 1, 2, 5, 6 3, 4, 7, 8 Total 14.57% 15.81% 15.16% 10.28% Age Group 12 to 17 21.22% 25.17% 23.03% 14.54% 18+ 13.76% 14.75% 14.24% 9.78% Gender Male 16.05% 16.47% 16.24% 13.87% Female 13.09% 15.23% 14.14% 6.93% Race/Ethnicity Hispanic 23.93% 15.81% 20.20% 12.33% Non-Hisp., Black 9.95% 15.10% 12.74% 9.99% Non-Hisp., All Other Races 14.45% 15.95% 15.15% 10.16% Education1 < High School 11.77% 11.27% 11.53% 14.57% High School 15.46% 11.39% 13.68% 10.63% > High School 13.11% 17.64% 15.41% 7.71% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4. .
Exhibit 7.3.16 Past 30-Day Use of Cigarettes, by Presence of Consistency Checks Respondent Characteristics ACASI Treatment Groups Comparison Group Consistency Checks Absent Consistency Checks Present Total ACASI 1997 Treatment Version: 1, 2, 5, 6 3, 4, 7, 8 Total 22.87% 29.86% 26.20% 30.45% Age Group 12 to 17 15.50% 16.83% 16.11% 18.56% 18+ 23.76% 31.33% 27.38% 31.84% Gender Male 27.94% 29.02% 28.43% 31.10% Female 17.84% 30.60% 24.11% 29.84% Race/Ethnicity Hispanic 20.83% 30.62% 25.33% 28.86% Non-Hisp., Black 17.91% 30.58% 24.79% 33.03% Non-Hisp., All Other Races 23.80% 29.64% 26.53% 30.13% Education1 < High School 33.42% 56.06% 44.01% 34.23% High School 28.48% 37.10% 32.25% 38.72% > High School 17.03% 21.24% 19.17% 26.50% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.3.17 Past 30-Day Use of Alcohol, by Presence of Consistency Checks Respondent Characteristics ACASI Treatment Groups Comparison Group Consistency Checks Absent Consistency Checks Present Total ACASI 1997 Treatment Version: 1, 2, 5, 6 3, 4, 7, 8 Total 44.80% 52.98% 48.70% 52.21% Age Group 12 to 17 16.16% 18.12% 17.06% 18.84% 18+ 48.27% 56.91% 52.40% 56.11% Gender Male 45.13% 57.93% 51.02% 60.23% Female 44.47% 48.65% 46.53% 44.70% Race/Ethnicity Hispanic 39.24% 36.19% 37.84% 40.79% Non-Hisp., Black 29.91% 39.68% 35.21% 41.19% Non-Hisp., All Other Races 47.54% 57.16% 52.02% 55.15% Education1 < High School 20.37% 42.78% 30.85% 40.55% High School 47.46% 47.90% 47.65% 55.62% > High School 57.89% 65.95% 61.99% 61.34% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.3.18 Past 30-Day Use of Marijuana, by Presence of Consistency Checks Respondent Characteristics ACASI Treatment Groups Comparison Group Consistency Checks Absent Consistency Checks Present Total ACASI 1997 Treatment Version: 1, 2, 5, 6 3, 4, 7, 8 Total 3.74% 5.84% 4.74% 5.28% Age Group 12 to 17 7.73% 9.11% 8.37% 7.30% 18+ 3.26% 5.48% 4.32% 5.04% Gender Male 4.89% 9.49% 7.01% 7.30% Female 2.60% 2.65% 2.62% 3.39% Race/Ethnicity Hispanic 3.82% 3.75% 3.79% 4.48% Non-Hisp., Black 3.61% 5.32% 4.54% 6.05% Non-Hisp., All Other Races 3.75% 6.13% 4.86% 5.21% Education1 < High School 6.06% 3.89% 5.05% 10.13% High School 4.68% 3.59% 4.21% 5.92% > High School 1.26% 6.99% 4.18% 2.86% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4. .
Exhibit 7.3.19 Past 30-Day Use of Cocaine, by Presence of Consistency Checks Respondent Characteristics ACASI Treatment Groups Comparison Group Consistency Checks Absent Consistency Checks Present Total ACASI 1997 Treatment Version: 1, 2, 5, 6 3, 4, 7, 8 Total 0.59% 0.54% 0.57% 0.59% Age Group 12 to 17 1.03% 0.22% 0.66% 1.09% 18+ 0.54% 0.57% 0.56% 0.53% Gender Male 0.32% 0.57% 0.43% 0.61% Female 0.87% 0.51% 0.69% 0.56% Race/Ethnicity Hispanic 1.30% 1.53% 1.40% 0.80% Non-Hisp., Black 0.70% 1.30% 1.03% 2.09% Non-Hisp., All Other Races 0.52% 0.30% 0.41% 0.30% Education1 < High School 2.09% 1.15% 1.65% 0.87% High School 0.59% 0.76% 0.67% 0.89% > High School 0.00% 0.31% 0.16% 0.18% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.3.20 Past 30-Day Use of Any Illicit Drug, by Presence of Consistency Checks Respondent Characteristics ACASI Treatment Groups Comparison Group Consistency Checks Absent Consistency Checks Present Total ACASI 1997 Treatment Version: 1, 2, 5, 6 3, 4, 7, 8 Total 4.66% 7.30% 5.91% 5.44% Age Group 12 to 17 10.44% 13.71% 11.95% 7.98% 18+ 3.96% 6.58% 5.21% 5.14% Gender Male 5.89% 10.80% 8.15% 7.68% Female 3.43% 4.23% 3.82% 3.34% Race/Ethnicity Hispanic 4.87% 5.19% 5.02% 4.60% Non-Hisp., Black 5.08% 8.17% 6.76% 6.45% Non-Hisp., All Other Races 4.57% 7.30% 5.84% 5.33% Education1 < High School 7.29% 5.13% 6.28% 9.46% High School 4.84% 5.42% 5.09% 5.94% > High School 2.20% 7.64% 4.97% 3.25% 1Education includes only individuals aged 18 or older. Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 1997 National Household Survey on Drug Abuse: Quarter 4.
Exhibit 7.3.21 Average Time to Complete Treatment Sections, by Whether Consistency Checks Are Used Average Time to Complete Consistency Check Present Consistency Check Absent Questionnaire Section n Time n Time Tobacco 972 1.6 1,005 1.6 Alcohol 972 3.4 1,004 3.2 Marijuana 972 0.9 1,004 0.9 Cocaine 972 0.5 1,004 0.5 Crack 515 0.4 585 0.4 Heroin 972 0.3 1,004 0.3 Hallucinogens 971 1.4 1,004 1.5 Inhalants 969 2.4 1,003 2.4 Total for Treatment Section 973 10.8 1,005 10.6 Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment.
Exhibit 7.3.22 Average Time to Complete Treatment Sections, by Whether Any Consistency Checks Were Triggered Anywhere in Instrument Average Time to Complete Consistency Check Triggered No Consistency Check Triggered Questionnaire Section n Time n Time Tobacco 227 2.2 745 1.5 Alcohol 228 4.4 744 3.1 Marijuana 228 1.2 744 0.8 Cocaine 228 0.6 744 0.4 Crack 145 0.4 370 0.4 Heroin 228 0.3 744 0.3 Hallucinogens 228 1.5 743 1.4 Inhalants 227 2.5 742 2.4 Total for Treatment Section 228 13.0 745 10.1 Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment.
Exhibit 7.3.23 Average Time to Complete Treatment Sections, by Whether Consistency Checks Were Triggered in Each Particular Section Average Time to Complete Consistency Check Triggered No Consistency Check Triggered Questionnaire Section n Time n Time Tobacco 68 3.2 904 1.5 Alcohol 137 4.8 835 3.1 Marijuana 33 2.4 939 0.9 Cocaine 9 2.0 963 0.4 Crack 4 1.5 511 0.4 Heroin 4 1.6 968 0.3 Hallucinogens 19 2.9 952 1.4 Inhalants 19 4.3 950 2.4 Total for Treatment Section 228 13.0 745 10.1 Source: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment.
Exhibit 7.3.24 Breakoff Rates, by Consistency Check Status Breakoff Rate Consistency Check Present Consistency Check Absent Cases Included n % n % Cases Ever Recorded as Breakoff Even if Completed Later 77 7.9 86 8.5 Cases Finalized as Breakoff 16 1.6 16 1.6 Total Number of Respondents Assigned to Group Treatment 975 1,007 Source: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment.
Exhibit 7.3.25 Respondent Reactions to CAI Interview, by Consistency Check Status Consistency Check Present Consistency Check Absent Item % n % n How Difficult to Use Computer? Very difficult 2.0 19 2.3 23 Somewhat difficult 6.4 61 6.3 63 Not at all difficult 91.6 879 91.4 907 Total 100.0 959 100.0 993 Able to Enter Answers Easily? Yes 90.0 864 86.6 860 No 10.0 96 13.4 133 Total 100.0 960 100.0 993 Wanted to Change Previous Answer But Did Not? Yes 18.2 174 18.5 183 No 81.8 783 81.5 806 Total 100.0 957 100.0 989 Level of Interest in Interview Very boring 6.2 59 7.0 69 Somewhat boring 10.2 97 13.2 130 Neither boring nor interesting 28.2 269 24.1 238 Somewhat interesting 34.5 329 34.4 340 Very interesting 20.9 200 21.3 210 Total 100.0 954 100.0 987 Accuracy and Completeness of Answers Very accurate and complete 84.4 807 82.1 813 Fairly accurate and complete 14.9 142 16.4 162 Not very accurate and complete 0.7 7 1.5 15 Total 100.0 956 100.0 990 Sources: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment.
Exhibit 7.3.26 Interviewer Reports of Respondent Difficulties, by Consistency Check Status Consistency Check Present Consistency Check Absent Item % n % n Respondent's Understanding of Interview No difficulty 84.4 810 81.4 807 Just a little difficulty 11.7 112 12.9 128 A fair amount of difficulty 3.1 30 4.3 42 A lot of difficulty 0.8 8 1.4 14 Total 100.0 960 100.0 991 How Cooperative Was Respondent? Very cooperative 92.4 888 92.1 913 Fairly cooperative 6.7 64 7.2 71 Not very cooperative 0.8 8 0.4 4 Openly hostile 0.1 1 0.3 3 Total 100.0 961 100.0 991 Respondent's Interest in ACASI Very interested 62.7 602 59.9 592 Somewhat interested 32.0 307 34.2 338 Not very interested 5.3 51 5.9 58 Total 100.0 960 100.0 988 How Necessary Was Tutorial? Necessary 23.0 221 22.4 221 Useful but not necessary 50.0 479 50.5 499 Unnecessary 27.0 260 27.1 268 Total 100.0 960 100.0 988 How Necessary Was Audio? Necessary 17.4 167 17.9 177 Useful but not necessary 48.1 461 45.3 448 Unnecessary 34.5 331 36.8 363 Total 100.0 959 100.0 988 How Often Did Respondent Let Answers Be Known? None of the time 82.9 796 81.0 800 A little of the time 12.6 121 13.5 133 Some of the time 2.8 27 3.5 35 A lot of the time 1.3 12 1.5 15 All of the time 0.4 4 0.5 5 Total 100.0 960 100.0 988 Source: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 7.4 Effect of ACASI Experimental Factors: Modeling Procedures and Effects on Prevalence In this section, we summarize the statistical methods used to assess ACASI experimental factors on the prevalence of drug use, the time to complete different parts of the interview, and the breakoff rates. Logistic regression and Cox proportional hazards models were used to evaluate the various ACASI experimental factors and to compare ACASI versus PAPI on binary and time-to-event responses. Due to the complex sample design, we used the SUrvey DAta ANalysis (SUDAAN) software package Release 7.5 (Shah, Barnwell, & Bieler, 1998) to account for stratification, clustering, and unequal weighting, where appropriate. SUDAAN's LOGISTIC and SURVIVAL procedures were used to fit the regression models. In addition, Release 6.12 of SAS software was used to estimate weighted prevalence rates of drug use, and the SAS procedures PHREG and LIFETEST were used to estimate the unweighted median time to complete different parts of the interview. The ACASI experimental factors evaluated in this report include the contingent questioning structure (single vs. multiple gate questions), the consistency checks (absent vs. present), and the multiple chances to report use (absent vs. present). Statistical models for evaluating the ACASI experimental factors also included the following covariates: the field interviewer's (FI's) rating of interview privacy (a three-level categorical variable describing how often the respondent let the FI know his or her answers, coded 1=none of the time, 2=some of the time, and 3=all of the time), the FI's rating of the degree of nonprivacy/distraction during the interview (coded 1-9, with Level 1 being the most private and Level 9 the least), age in years (12 to 17 vs. 18 or older), gender (male vs. female), education level (less than high school, high school, greater than high school), and race/ethnicity (Hispanic, black, and white). In addition to evaluating the main effects of the three experimental factors (contingent questioning structures, multiple use questions, and consistency checks) and covariates, we also evaluated all two-way and three-way interactions among the three ACASI experimental factors. To compare the ACASI experimental factors on prevalence of drug use, breakoff rates, and the time to complete different parts of the interview, a model containing all the main effects, covariates, and interactions was fit first: Model 1: Main Effects + Covariates + Interactions ACASI Main Effects (3 degrees of freedom): (a) contingent questioning, (b) multiple use, and (c) consistency checks. Covariates (9 degrees of freedom): (a) gender, (b) age group, (c) race/ethnicity, (d) education, (e) letting FI know answers, and (f) degree of distraction/nonprivacy. Interactions (4 degrees of freedom): (a) contingent questioning * multiple use, (b) contingent questioning * consistency checks, (c) multiple use * consistency checks, and (d) contingent questioning * multiple use * consistency checks. Wald chi-square tests were used to evaluate the main effects, covariates, and interactions of interest. This interaction model was used to determine if the global 4 degrees-of-freedom interaction effect (containing all two-way and three-way interactions among the ACASI factors) was statistically significant. If the global interaction effect was not significant (p>0.10), all two-way and three-way interactions were removed, and a new main effects model (Model 2 below) was fit containing only ACASI main effects and covariates. Model 2: Main Effects + Covariates ACASI Main Effects (3 degrees of freedom): (a) contingent questioning, (b) multiple use, and (c) consistency checks. Covariates (9 degrees of freedom): (a) gender, (b) age group, (c) race/ethnicity, (d) education, (e) letting FI know answers, and (f) degree of distraction/nonprivacy. The ACASI experimental factors were then evaluated in the reduced main effects model. In the reduced model, each main effect was automatically adjusted for all other main effects and covariates present in the model. However, if a significant global interaction effect (4 degrees of freedom) was detected (p<0.10) in Model 1, further modeling was done to evaluate specifically which two-way and possibly three-way interaction effect(s) were statistically significant. When we determined that a particular ACASI experimental factor, X, significantly interacted with another ACASI factor, Y, then factor X was evaluated separately within each level of factor Y (these effects are sometimes called "simple effects" or "effect slices"). The Cox proportional hazards model was used to detect overall heterogeneity in time-to-completion distributions among the ACASI experimental factors. Median event times can be computed from the model. The Cox proportional hazards model is stated as follows: where t represents the time to event, Using this model, we were able to quantify the relative effect of treatment combinations on the event times. The model requires the user to supply each respondent's event time, an indicator for censoring ("yes" vs. "no"), and a set of covariate values. All event times, censored and complete, were used in the analysis. A Wald chi-square test was used to evaluate the effect of treatment on event time. The logistic regression model was used to examine the results for prevalence of drug use. Exhibit 7.4.1 summarizes the statistically significant ACASI treatment effects found. During the analyses, we looked at both unweighted and weighted data for cigarettes, alcohol, marijuana, and cocaine. Exhibit 7.4.1 contains the outcomes of interest, the model effects, the p value(s) and odds ratio(s) corresponding to the effects, and the adjusted prevalence rate. Prevalence rates and model effects were adjusted for all other variables in the model. Odds ratios greater than 1.0 indicate increased prevalence in a particular treatment group versus the reference cell, while odds ratios less than 1.0 indicate reduced prevalence in a particular treatment group. In the discussion, statistical significance refers to p<0.05 for main effects and p<0.10 for interactions, unless otherwise specified. Marginal significance refers to 0.05< p<0.10. The following summarizes the significant results, both unweighted and weighted: Cigarettes The presence of multiple chances to report use significantly reduced the reported prevalence of lifetime use from 59.1% to 53.7% (unweighted only). The reported prevalence of past month use (weighted only) was marginally increased (0.05< p< 0.10) when respondents had multiple chances to report use (19.9% vs. 29.4% for absent vs. present) and when consistency checks were present (20.4% vs. 28.8% for absent vs. present). Alcohol The presence of consistency checks marginally increased (0.05< p<0.10) the reported prevalence of past year use (weighted only) from 67.2% to 74.6%. The presence of multiple chances to report use significantly reduced the reported prevalence of past month use (unweighted only) from 29.7% to 25.2%. Marijuana The multiple gate questions significantly reduced the reported prevalence of past year use (weighted only) from 10.8% to 6.2%. The presence of consistency checks significantly increased the reported prevalence of past month use (unweighted only) from 4.7% to 8.1% but only for the multiple gate version (this was reflected in a significant interaction effect between the consistency checks and the contingent questioning structure). Cocaine Lifetime use was significantly increased in the presence of multiple chances to report use (unweighted only) from 2.9% to 5.5% but only for the multiple gate questions (there was significant interaction between the multiple chances to report use and the type of contingent questioning used). Lifetime use was significantly reduced when multiple gate questions were used (weighted only, 14.6% vs. 7.4% for single vs. multiple gate). Past year use was significantly increased in the presence of multiple chances to report use (unweighted and weighted) but only for the multiple gate questions (there was significant interaction between the multiple chances to report use and the contingent questioning structure). Past year use was significantly reduced in the presence of consistency checks (unweighted and weighted) but only in the presence of multiple chances to report use (there was significant interaction between the consistency checks and the multiple use treatment). Past month use was significantly increased in the presence of consistency checks (unweighted and weighted) but only for the multiple gate questions (there was significant interaction between the consistency checks and the contingent questioning structure). Past month use was marginally reduced (0.05<p<0.10, unweighted only) in the presence of consistency checks butonly when respondents had multiple chances to report use (there was significant interaction between the consistency checks and the multiple chances). Any Illicit Drug Use Lifetime use was marginally reduced (0.05< p<0.10) in the presence of multiple chances to report use, from 43.1% absent to 38.5% present (unweighted only).
Exhibit 7.4.1 Summary of Statistically Significant Modeling Results: Prevalence of Drug Use Among ACASI Treatment Groups Outcome Unweighted or Weighted Effect p Value Odds Ratio Adjusted Prevalence Rate Cigarettes Lifetime Unweighted Multiple Use: Present vs. Absent 0.0144 0.80 59.1% Absent 53.7% Present Past Month Weighted Multiple Use: Present vs. Absent 0.0780 1.67 19.9% Absent 29.4% Present Consistency Checks: Present vs. Absent 0.0675 1.58 20.4% Absent 28.8% Present Alcohol Past Year Weighted Consistency Checks: Present vs. Absent 0.0817 1.44 67.2% Absent 74.6% Present Past Month Unweighted Multiple Use: Present vs. Absent 0.0245 0.80 29.7% Absent 25.2% Present Marijuana Past Year Weighted Multiple vs. Single Gate 0.0179 0.54 10.8% Single 6.2% Multiple Past Month Unweighted Consistency Checks: Present vs. Absent (Routing=Multiple Gate) 0.0237 1.93 4.7% Absent 8.1% Present Cocaine Lifetime Unweighted Multiple Use: Present vs. Absent (Routing=Multiple Gate) 0.0165 2.45 2.9% Absent 5.5% Present Lifetime Weighted Multiple vs. Single Gate 0.0280 0.47 14.6% Single 7.4% Multiple Past Year Unweighted Multiple Use: Present vs. Absent (Routing=Multiple Gate) 0.0124 -- 1.2% Absent 2.5% Present Consistency Check: Present vs. Absent (Multiple Use=Present) 0.0162 -- 3.3% Absent 1.2% Present Past Year Weighted Multiple Use: Present vs. Absent (Routing=Multiple Gate) 0.0079 -- 0.4% Absent 1.5% Present Consistency Check: Present vs. Absent (Multiple Use=Present) 0.0079 -- 2.3% Absent 0.6% Present Past Month Unweighted Consistency Check: Present vs. Absent (Routing=Multiple Gate) 0.0397 -- 0.24% Absent 0.61% Present Consistency Check: Present vs. Absent (Multiple Use=Present) 0.0690 -- 0.88% Absent 0.26% Present Past Month Weighted Consistency Check: Present vs. Absent (Routing=Multiple Gate) 0.0032 11.03 0.07% Absent 0.44% Present Any Illicit Drug Use Lifetime Unweighted Multiple Use: Present vs. Absent 0.0633 0.88 43.1% Absent 38.5% Present 1 Any illicit drug includes marijuana, cocaine, crack, heroin, inhalants, hallucinogens, and nonmedical use of analgesics, sedatives, stimulants, and tranquilizers. Source: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures: 1997 Field Experiment. 7.5 Effect of ACASI Experimental Factors on the Time to Complete Different Parts of the Interview We calculated the unweighted median time to complete different parts of the interview for each of the eight ACASI treatment combinations. Cox Proportional Hazards Regression Modeling was used to evaluate the effects of ACASI experimental factors on the completion times for the following three outcomes of interest: the total core time (all CAI sections through the sedatives section), the core experimental time (tobacco through inhalants sections), and the remaining ACASI time (from inhalants to the end). For each time variable, respondents who were not at risk at the start of the reference period had a missing value for that time variable and were therefore not included in the analysis. Respondents who broke off during the reference period were censored during that time and had a censoring indicator value corresponding to "yes." Their time value contains partial information that was used in this analysis. The following information summarizes the significant results for each variable. We fit models using both weighted and unweighted data; however, only the unweighted results are presented because they apply to the actual sample. This is most appropriate for an operational measure. 7.5.1 Total Core Time, Unweighted Multiple gate versions significantly delayed the time to completion compared to the single gate version (18.65 vs. 17.58 minutes with an estimated hazard ratio of 0.84, p<0.01). Multiple chances to report use significantly delayed the time to completion (the median time to complete was 18.42 vs. 17.77 minutes with an estimated hazard ratio of 0.90, p<0.01). There was no significant effect on time to complete based on whether consistency checks were present or absent. Among the covariates, age, education, race/ethnicity, and the degree of non-privacy/distraction had significant effects on the time to complete, with significantly shortened times for those aged 12 to 17 years compared to those aged 18 or older but significantly delayed times for those with less thana high school education and high school graduates compared to those with more than a high school education, for Hispanics and blacks compared to whites, and for every unit increase in distraction. 7.5.2 Core Treatment Time (Tobacco Through Inhalants), Unweighted Multiple gate versions significantly delayed the time to completion compared to the single gate version (the median time to complete was 10.6 vs. 9.77 minutes for multiple vs. single gate, respectively, with the estimated hazard ratio at 0.80, p<0.01). Multiple chances to report use significantly delayed the time to completion (the median time to complete was 10.3 vs. 9.95 minutes for presence vs. absence, respectively, with the hazard ratio at 0.89, p=0.014). The presence of consistency checks also significantly delayed the time to completion (the median time to complete was 10.27 vs. 9.97 minutes for the presence vs. absence of consistency checks, with an estimated hazard ratio of 0.91, p=0.028). Among the covariates, age group, education, race/ethnicity, letting the FI know the answers, and the degree of nonprivacy/distraction had significant effects on time to complete, with significantly shortened times for those aged 12 to 17 years compared to those aged 18 years or older, but with significantly delayed times for those with less than high school education and high school graduates compared to those with more than a high school education, Hispanics compared to whites, letting the FI know the answers some of the time compared to all of the time, and for every unit increase in distraction. Hazard ratios for shortened times were greater than 1.0, while hazard ratios for delayed times were less than 1.0. We examined the impact of the time required to complete the core on subsequent breakoffs. The analysis was based on only those respondents who were not censored before or during the core treatment sections (n=1,968) or, in other words, at risk for subsequent breakoff. No other covariates or treatment factors were included in the model. Results indicate that subsequent breakoff after core treatment was significantly associated with a delay in the median time to complete the core treatment. The median times were 10.7 versus 10.05 minutes for the presence versus absence of subsequent breakoff, with an estimated hazard ratio of 0.84, p=0.033. 7.5.3 Remaining ACASI Time After Inhalants, Unweighted Although ACASI treatments did not vary in this section, we examined these times to determine if the treatment assigned to a respondent in the tobacco through inhalants sections had a carryover effect. None of the previously assigned ACASI experimental factors had a significant effect on the time to complete the remaining ACASI after the inhalants section. Among the covariates, education, race/ethnicity, and the degree of non-privacy/distraction had significant effects on the time to complete, with significantly delayed times for those with less than a high school education and high school graduates compared to those with a high school education, Hispanics and blacks compared to whites, and for every unit increase in distraction. Hazard ratios for delayed times were less than 1.0. Although there were multiple results that were significantly different, none of the time differences was large enough to point toward choosing one method over another. 7.6 Effect of ACASI Experimental Factors on Breakoff Rates In this section, we describe the results of logistic regression modeling to evaluate the effects of ACASI experimental factors on the incidence of breakoffs anywhere in the interview. Some additional information corresponding to these analyses and results follows. We present only unweighted modeling results. A table of results (Exhibit 7.6.1) contains the model effects and their corresponding p value(s) and odds ratio(s). Odds ratios greater than 1.0 indicate an increase in the probability of a breakoff for a particular group compared to the reference group, and an odds ratio less than 1.0 indicates a reduction in the probability of a breakoff. Effects are adjusted for all other variables in the model, unless otherwise indicated. Statistical significance refers to p<0.05, unless otherwise specified. The 12 to 17 year olds were classified as less than high school graduates to include all respondents in one analysis. Privacy covariates were not included in this model because their missing values would have removed all but four breakoffs from the analysis. A total of 32 breakoff cases out of 1,982 respondents were used in this analysis. The following information summarizes the results from this analysis. None of the ACASI experimental factors significantly affected the incidence of breakoffs. None of the covariates significantly affected the incidence of breakoffs.
Exhibit 7.6.1 Logistic Regression Modeling Results: Breakoff Anywhere in the Interview (Unweighted Results) Outcome Effect Contrast p Value Odds Ratio Intstat: Breakoff indicator (1=yes; 0=no) Interactions Involving Main Effects (4 df): - 0.1372 -- Contingent Questioning Structure Multiple Gate vs. Single Gate 0.6170 1.20 Multiple Chance Present vs. Absent 0.8004 1.10 Consistency Checks Present vs. Absent 0.8636 1.05 Gender Male vs. Female 0.3224 1.49 Age Group 12-17 vs. 18+ 0.9633 1.03 Education Overall (2 df) 0.7550 < High School vs. > High School 0.7139 0.76 High School vs. > High School 0.4573 0.61 Race Overall (2 df) 0.9692 Hispanic vs. White 0.8876 0.92 Black vs. White 0.8653 1.07 Note: There were 32 break off cases out of 1,982 respondents. Privacy covariates are not included in this model because their missing values would remove all but four break off from the analysis. Source: National Household Survey on Drug Abuse: Development of Computer-Assisted Interviewing Procedures; 1997 Field Experiment. 16 Only possible for respondents assigned to the multiple use treatment. 17 Patterns of inconsistent reporting are discussed more fully in Sections 7.1.2, 7.2.2, and 7.3.2.
This page was last updated on June 16, 2008.
(Treatment Versions:
1, 2, 3, 4)
(Treatment Versions:
5, 6 ,7, 8)
(minutes)
(minutes)
Treatment Versions:
1, 2, 3, 4
Treatment Versions:
5, 6, 7, 8
(Treatment Versions:
1, 2, 3, 4)
(Treatment Versions:
5, 6, 7, 8)
Detailed Exhibits for Section 7.2
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
(Treatment Versions:
1, 2, 3, 4)
(Treatment Versions:
5, 6, 7, 8)
Comparison
Variable
Liberal
NHSDA
Variable
Variable
Liberal
NHSDA
Variable
(minutes)
(minutes)
Detailed Exhibits for Section 7.3
at First Use Equals Current Age
Not Verified as Age of First
Use
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
Quarter 4
PAPI/SAQ
(minutes)
(minutes)
(minutes)
(minutes)
(minutes)
(minutes)
is the linear combination of covariate effects, and 
is the relative risk (or hazard ratio) for the event at time t for respondents in different ACASI treatment groups.
