Objective: To determine the efficacy of a spit tobacco (ST) intervention designed to promote ST cessation and discourage ST initiation among male high school baseball athletes.
Methods: This study was a cluster-randomized controlled trial. Forty-four randomly selected high schools in rural California were randomized within strata (prevalence of ST use and number and size of baseball teams) to either the intervention or the control group. Ninety-three percent of eligible baseball athletes participated, yielding 516 subjects in 22 intervention schools and 568 subjects in 22 control schools. Prevalences of sustained ST cessation and ST use initiation over 1 year were assessed by self-report. Multivariate logistic regression models for clustered responses were used to test the null hypotheses of no association between group and the two outcomes, adjusted for the stratified design and baseline imbalances between groups in significant predictors of ST use.
Results: Prevalence of cessation was 27% in intervention high schools and 14% in control high schools (odds ratio (OR)=2.29; 95% confidence interval (CI), 1.36-3.87). The intervention was especially effective in promoting cessation among those who, at baseline, lacked confidence that they could quit (OR=6.4; 95% CI, 1.0-4.3), among freshmen (OR=15; 95% CI, 0.9-260), and among nonsmokers (OR=3.2; 95% CI, 0.9-11). There was no significant difference between groups in the prevalence of ST initiation.
Conclusions: This intervention was effective in promoting ST cessation, but was ineffective in preventing initiation of ST use by nonusers.