Smoking reductions and increased self-efficacy in a randomized controlled trial of smoking abstinence-contingent incentives in residential substance abuse treatment patients

Abstract

Introduction: Individuals with substance use disorders (SUDs) experience increased smoking-related morbidity and mortality but severely compromised smoking treatment benefits. Residential SUD treatment settings may be particularly positioned to target smoking, with ever-increasing smoking bans and culture shifts, but most smokers continue smoking. This study examined the effects of contingency management (CM) for increasing smoking abstinence in residential patients.

Methods: Smokers interested in quitting were recruited from a residential SUD program for men and were randomized to frequent smoking monitoring with behavioral support (monitoring; n = 21) or that plus smoking abstinence-contingent (expired carbon monoxide [CO] ≤ 6 ppm; urinary cotinine ≤ 30ng/ml) incentives (CM, n = 24) for 4 weeks. After setting a quit date, procedures included daily behavioral support and smoking self-reports, 2 CO samples (a.m./p.m.) Monday through Friday, and cotinine tests on Mondays. CM participants received escalating draws for prizes ($1, $20, and $100 values) for negative tests; positive and missed samples reset draws. Follow-ups involved samples, self-reported smoking, and self-efficacy (weeks 4, 8, 12, and 24).

Results: Percent days CO-negative was higher with CM (median [interquartile range] 51.7% [62.8%]) compared to monitoring (0% [32.1%]) (p = .002). Cigarettes per day declined and point-prevalence abstinence increased through follow-up (p < .01), without significant group by time effects (p > .05). Abstinence self-efficacy increased overall during the intervention and more with CM compared to monitoring and was associated with abstinence across conditions through follow-up.

Conclusions: CM improved some measures of response to smoking treatment in residential SUD patients.

Figure 1.

The flow of participants from the point of initial contact through data analysis per Consolidating Standards of Reporting Trials (CONSORT) guidelines. CM = contingency management.

Figure 2.

Box and whisker plot of percent of days CO-negative (CO ≤ 6 ppm) in the monitoring (n = 21) and CM (n = 24) conditions. In the monitoring condition, the median was zero. The ends of the whiskers are the minimum (bottom) and maximum (top) values save the outlier, defined as any value more than 1.5 times the length of the box from either end of the box and indicated here by an open circle for visual purposes only. All data were included in analyses. × indicates the mean; * indicates significant differences between study conditions at p = .002 for the analysis omitting days of missed samples, and p = .008 for the analysis coding days with missed samples smoking-positive. CM = contingency management; CO = carbon monoxide.