LAUSR

AIM To evaluate the effectiveness of home-based contingency management (CM) in improving abstinence in an incentive-dependent manner among alcoholic individuals. METHODS A 12-week, home-visit (HV) only controlled, randomized incentive-ranging trial of 161 adults with current alcohol dependence was recruited using social network theory techniques. Participants randomly received HV, low- (CM-L) or higher-magnitude CM (CM-H). Community health workers made regular home visits, monitored drinking behavior and delivered CM as appropriate. Two follow-up visits at weeks 13 and 16 were conducted to assess whether abstinence would still be maintained after the interventions discontinued. Rates of continuous reported abstinence (primary), numbers of positive breath samples (secondary) over the intervention period and rates of prolonged reported abstinence (secondary) were evaluated. RESULTS CM did not significantly improve the rates of continuous reported abstinence across the 12-week intervention period (odds ratio (OR) for trend 1.2, 95% confidence interval (CI) 0.7-2.1, P = 0.601). There was a significant reduction, however, in the average number of positive breath samples submitted by the CM-H group (generalized linear model, β -0.5, 95% CI -0.9 to -0.2, P = 0.005). The CM-H arm also had a significantly higher abstinence rate during the follow-up period (OR 3.4, 95% CI 1.3-8.8, P = 0.013). Event history model suggested that the CM-H condition had significantly higher chances of achieving renewed abstinence across the study period (OR 2.0, 95% CI 1.3-3.2, P = 0.003). CONCLUSIONS Home-based CM with sufficient incentive is promising in reducing alcohol use and in improving rates of abstinence over time. Allowing for a certain grace period may better capture the delayed treatment effect of home-based CM.