Clinical trial NCT01040260
Conditions: Tobacco Use Cessation
Keywords: tobacco use disorder
Sponsor: University of California, San Francisco
Start date: 2009-06-01; Completion date: 2012-05-01
Enrollment: 103 participants; Allocation: RANDOMIZED; Intervention model: PARALLEL

Brief summary:
An innovative low-cost form of contingency management has been developed in which participants receive the chance to draw vouchers from a fish bowl depending on whether or not their abstinence from tobacco is confirmed by expired-air carbon monoxide. The vouchers can be redeemed for prizes of varying value. This form of contingency management has been shown to be effective in the treatment of a variety of substance use disorders, but has not been investigated in a clinical trial focusing on smoking cessation. Thus, the primary purpose of the proposed study will be to investigate the effects of a low-cost prize-based form of contingency management in the treatment of nicotine dependence. To accomplish this objective, we enrolled 103 current smokers into the study. The participants in Study Arm 1 received the contingency management intervention for 8 weeks, and the participants in Study Arm 2 had their smoking status assessed but did not receive the contingency management intervention. Both interventions received brief counseling and nicotine replacement therapy. The counseling was conducted in two 60-minute individual sessions scheduled one week apart with two follow-up phone calls at weeks 3, 4, and 6.

The primary outcome for this study was biochemically-validated smoking status at 3 months (end of treatment), and at 6- and 12-month follow-up. Both continuous and point-prevalent abstinence rates were determined. Saliva cotinine levels were measured in all participants reporting abstinence at each assessment. This study had 80% power to detect a 10% absolute difference in smoking cessation rates between the two treatment conditions (i.e., a 28% quit rate in Study Arm 1 versus a 18% quit rate in Study Arm 2) with alpha set at 0.05. These estimates included an anticipated 15% loss to follow-up over the 12-month study period.

Detailed description:
Contingency management as a treatment for substance use disorders involves the use of tangible rewards for confirmed abstinence. There is preliminary evidence that contingency management shows promise as a smoking cessation intervention. An innovative low-cost form of contingency management has been developed in which participants receive the chance to draw vouchers from a fish bowl depending on whether or not their abstinence from tobacco is confirmed by expired-air carbon monoxide. The vouchers can be redeemed for prizes of varying value. This form of contingency management has been shown to be effective in the treatment of a variety of substance use disorders, but has not been investigated in a clinical trial focusing on smoking cessation. Thus, the primary purpose of the proposed study was to investigate the effects of a low-cost prize-based form of contingency management in the treatment of nicotine dependence. To accomplish this objective, we enrolled 103 current smokers into the study. The participants in Study Arm 1 received the contingency management intervention for 8 weeks, and the participants in Study Arm 2 had their smoking status assessed but did not receive the contingency management intervention. Both interventions received brief counseling and nicotine replacement therapy. The counseling was conducted in two 60-minute individual sessions scheduled one week apart with two follow-up phone calls at weeks 3, 4, and 6.

The primary outcome for this study was biochemically-validated smoking status at 3 months (end of treatment), and at 6- and 12-month follow-up. Both continuous and point-prevalent abstinence rates were determined. Saliva cotinine levels were measured in all participants reporting abstinence at each assessment. This study had 80% power to detect a 10% absolute difference in smoking cessation rates between the two treatment conditions (i.e., a 28% quit rate in Study Arm 1 versus a 18% quit rate in Study Arm 2) with alpha set at 0.05. These estimates included an anticipated 15% loss to follow-up over the 12-month study period.

Arms: arm 1: Use of tangible rewards for verified abstinence arm 2: Counseling plus nicotine patches
Interventions: intervention 1: Counseling intervention 2: Contingency management intervention 3: Nicotine patches
Intervention descriptions: intervention 1: Smoking cessation counseling intervention 2: Use of tangible rewards for abstinence from smoking intervention 3: Nicotine patches

Protocol documents: