Abstract
AIMS: To test whether psychological factors predict male smokeless tobacco (SLT) initiation and cessation longitudinally. DESIGN: Sixteen-year longitudinal design with 95% retention at year 6 and 82% at year 16. SETTING: Forty Washington State school districts. PARTICIPANTS: SLT use data were gathered on a cohort of adolescents (91% Caucasian). For SLT initiation, the sample size was 2468. For SLT cessation, sample sizes were 219 (age 20 outcome) and 192 (age 28 outcome). MEASUREMENTS: Self-reported psychological measures of parental disobedience ('parent non-compliance'), peer influence ('friend compliance'), rebelliousness and thrill-seeking were taken at ages 12 and 18. SLT use was measured at ages 12, 18, 20 and 28 years. FINDINGS: For SLT initiation, scoring highly on the following psychological factors at age 12 at least doubled the odds of daily SLT use at age 18 (P < 0.001): friend compliance [odds ratio (OR): 2.56, 95% confidence interval (CI): 1.78-3.68), rebelliousness (OR: 2.16, 95% CI: 1.46-3.19) and thrill-seeking (OR: 2.33, 95% CI: 1.45-3.75). For SLT cessation, none of the psychological factors at age 18 predicted SLT cessation at age 20 or 28 (P value range: 0.06-0.84). CONCLUSION: Peer influence, rebelliousness, and thrill-seeking appear to predict smokeless tobacco initiation strongly among male youth in the United States.