A randomized clinical trial to evaluate the efficacy of contingency management for treatment of waterpipe tobacco addiction.

BACKGROUND AND OBJECTIVES: Unlike cigarette smoking cessation, waterpipe tobacco smoking cessation is relatively understudied. The objective of this randomized clinical trial was to examine the efficacy of contingency management (CM) for promoting initial waterpipe smoking abstinence. METHODS: The study used a two-group, repeated measures design. Participants attended 10 visits (two visits per week, on Mondays and Thursdays) across 5 weeks. Thirty-nine adult waterpipe tobacco users who did not smoke cigarettes and were not planning on quitting waterpipe tobacco smoking were randomly assigned to either the contingent (n = 19) or non-contingent (n = 20) groups. Contingent group received monetary rewards based on negative salivary cotinine results. Earning rewards started at $14 and increased by $.50 with each subsequent negative sample for a maximum $192.50. Non-contingent group earned rewards independent of salivary cotinine results. Prolonged abstinence was defined as having negative salivary cotinine results for eight or more visits (two lapses were allowed); and 7-day point prevalence was defined as having negative salivary cotinine results at visit 9 and 10 (final week). RESULTS: The prolonged abstinence rate in the contingent and non-contingent groups were 42.1% and 5.0%, respectively, (p = .008). The 7-day point prevalence in the contingent and non-contingent were 47.4% and 5.0%, respectively, (p = .003). DISCUSSION AND CONCLUSIONS: Rewards contingent on biochemically verified abstinence promote initial waterpipe tobacco cessation. This is useful information for consideration in future cessation programs for waterpipe smokers. SCIENTIFIC SIGNIFICANCE: CM strategy may have potential benefit in addressing waterpipe tobacco smoking in non-treatment seeking adults. (Am J Addict 2018;27:202-209).