March 5, 2009

Smokeless Tobacco Use, Initiation, and Relationship to Cigarette Smoking: 2002 to 2007

Smokeless tobacco products consist of tobacco or a tobacco blend that is chewed, placed in the oral cavity outside the gums, or inhaled or snorted through the nose rather than smoked. The Surgeon General reported that use of smokeless tobacco "is not a safe substitute for cigarette smoking, can cause cancer and a number of noncancerous oral conditions, and can lead to nicotine addiction and dependence."¹

The National Survey on Drug Use and Health (NSDUH) asks persons aged 12 or older about their substance use, including their use of tobacco products. The questions on tobacco products focus on cigarettes, cigars, pipe tobacco, and smokeless tobacco (i.e., chewing tobacco and snuff). Respondents who used these substances are asked when they first used them.

This issue of The NSDUH Report examines smokeless tobacco use and its relationship to cigarette smoking among persons aged 12 or older. The first section presents information on trends in the use of smokeless tobacco using NSDUH data from 2002 to 2007. Unless otherwise noted, all other findings are annual averages based on data from the combined 2002 to 2007 surveys.

Among persons aged 12 or older, past month smokeless tobacco use remained relatively stable in the range of 3.0 to 3.3 percent between 2002 and 2007 (Figure 1). This finding was consistent across most gender and age groups. However, among males aged 12 to 17, past month smokeless tobacco use increased significantly—from 3.4 percent in 2002 to 4.4 percent in 2007.

Figure 1. Percentages of Persons Aged 12 or Older Who Used Smokeless Tobacco in the Past Month: 2002 to 2007

Among persons aged 12 or older, the rate of recent initiation of smokeless tobacco use (i.e., first-time use of smokeless tobacco in the 12 months before the survey interview among all persons who had not previously used it) showed a modest, but statistically significant increase between 2002 and 2007 (from 0.5 to 0.6 percent) (Table 1). Initiation rates were higher in 2007 than in 2002 among males aged 12 to 17 and males aged 18 to 25. Among females, there were no statistically significant changes in initiation rates for any age group over the 6-year period.

Combined 2002 to 2007 data indicate that an annual average of 3.2 percent of persons aged 12 or older (an estimated 7.8 million persons) used smokeless tobacco in the past month. Certain demographic subgroups were more likely to use smokeless tobacco than others. It was more likely to be used among persons aged 18 to 25 than among 12 to 17 year olds and those 26 or older (Table 2). Males were more likely than females to have used smokeless tobacco (6.2 vs. 0.4 percent). American Indians or Alaska Natives were more likely than persons in any other racial/ethnic category to have used smokeless tobacco.

Rates also varied by geographic characteristics. Past month smokeless tobacco use was highest among persons who lived in completely rural and less urbanized counties in non-metropolitan areas and lowest among persons who lived in large metropolitan areas. Persons who lived in the South and Midwest were more likely than persons who lived in the West and Northeast to have used smokeless tobacco.

Combined data from 2002 to 2007 indicate that an annual average of 1.1 million persons initiated use of smokeless tobacco in the past 12 months. This represents 0.6 percent of those at risk for initiation (i.e., those who had not previously used smokeless tobacco). Initiation of smokeless tobacco in the past 12 months was more likely to occur among youths aged 12 to 17 than among young adults aged 18 to 25 (2.2 vs. 1.8 percent). Both of these age groups had higher rates of initiation than adults aged 26 or older (0.1 percent). Among those at risk for initiation of smokeless tobacco use, the rate of recent initiation was higher among males than females (1.0 vs. 0.2 percent).

Combined data from 2002 to 2007 indicate that 85.8 percent of past month smokeless tobacco users used cigarettes at some time in their lives, and 38.8 percent used cigarettes in the past month (Figure 2). The rate of current cigarette use was 66.9 percent among past month smokeless tobacco users aged 18 to 25, 52.8 percent among those aged 12 to 17, and 29.3 percent among those aged 26 or older.

Figure 2. Percentages of Cigarette Use among Past Month Smokeless Tobacco Users, by Age Group: 2002 to 2007

Combined 2004 to 2007 data indicate that, among persons who had used both smokeless tobacco and cigarettes in their lifetime, 31.8 percent started using smokeless tobacco first, 65.5 percent started using cigarettes first, and 2.7 percent initiated use of smokeless tobacco and cigarettes at about the same time (i.e., within the same month) (Figure 3). Nearly half (47.0 percent) of past month smokeless tobacco users were former cigarette users (i.e., used cigarettes at some time in the past, but not in the past month). Some initiates of smokeless tobacco use may be cigarette smokers who are substituting smokeless tobacco as a way to quit smoking. Among daily smokers who initiated smokeless tobacco use, 88.1 percent were still smoking daily 6 months later.²

Figure 3. Sequence of Initiation of Smokeless Tobacco and Cigarette Use among Persons Who Had Ever Used Both Smokeless Tobacco and Cigarettes: 2004 to 2007

Smokeless tobacco contains 28 cancer-causing agents and has been linked to oral cancer and increased risk of death from cardiovascular diseases.^{3, 4} Chewing tobacco leads to nicotine dependence, as does cigarette use. This report indicates that although rates of use remained stable between 2002 and 2007, there were increases among certain subpopulations—in particular, among adolescent males. Most smokeless tobacco users smoked cigarettes at some time in their lives, and most people who used both cigarettes and smokeless tobacco had used cigarettes first. It is important for current and former cigarette users to understand that smokeless tobacco use is not a healthy alternative to cigarette smoking.