Evidence against a gateway from smokeless tobacco use to smoking

It has been suggested that smokeless tobacco (ST) use by young people induces them to become smokers, but direct evidence is lacking.

Information in the 2003, 2005, and 2007 National Survey on Drug Use and Health was used to determine the prevalence of smoking among White men (aged 18+ years) and boys (aged 16-17 years) who had started tobacco use with ST, cigarettes, or with both products.

Among White men, the majority (82.2%, CI = 81.3-83.1) of ever-smokers were cigarette initiators, while 10.7% (CI = 10.0-11.4) were ST initiators and 7.1% (CI = 6.6-7.7) were dual initiators. The prevalence of current smoking among cigarette initiators was 34.7% (CI = 33.7-35.7). The prevalence among dual initiators was 10% higher (prevalence ratio [PR] = 1.10, CI = 1.04 - 1.16), while the prevalence among ST initiators was significantly lower (PR = 0.80, CI = 0.77 - 0.84). Among White boys, almost 92% were either cigarette or dual initiators. The prevalence of current smoking among cigarette initiators was 42.8% (CI = 40.5-45.2). In comparison, the prevalence among ST initiators was less than half (PR = 0.43, CI = 0.36-0.52).

ST use has played virtually no role in smoking initiation among White men and boys, the demographic groups among which ST use is most prevalent. There is evidence that, compared with cigarette initiators, ST initiators are significantly less likely to smoke. This suggests that ST may play a protective role.