Randomized trial of four financial-incentive programs for smoking cessation

Abstract

Background: Financial incentives promote many health behaviors, but effective ways to deliver health incentives remain uncertain.

Methods: We randomly assigned CVS Caremark employees and their relatives and friends to one of four incentive programs or to usual care for smoking cessation. Two of the incentive programs targeted individuals, and two targeted groups of six participants. One of the individual-oriented programs and one of the group-oriented programs entailed rewards of approximately $800 for smoking cessation; the others entailed refundable deposits of $150 plus $650 in reward payments for successful participants. Usual care included informational resources and free smoking-cessation aids.

Results: Overall, 2538 participants were enrolled. Of those assigned to reward-based programs, 90.0% accepted the assignment, as compared with 13.7% of those assigned to deposit-based programs (P<0.001). In intention-to-treat analyses, rates of sustained abstinence from smoking through 6 months were higher with each of the four incentive programs (range, 9.4 to 16.0%) than with usual care (6.0%) (P<0.05 for all comparisons); the superiority of reward-based programs was sustained through 12 months. Group-oriented and individual-oriented programs were associated with similar 6-month abstinence rates (13.7% and 12.1%, respectively; P=0.29). Reward-based programs were associated with higher abstinence rates than deposit-based programs (15.7% vs. 10.2%, P<0.001). However, in instrumental-variable analyses that accounted for differential acceptance, the rate of abstinence at 6 months was 13.2 percentage points (95% confidence interval, 3.1 to 22.8) higher in the deposit-based programs than in the reward-based programs among the estimated 13.7% of the participants who would accept participation in either type of program.

Conclusions: Reward-based programs were much more commonly accepted than deposit-based programs, leading to higher rates of sustained abstinence from smoking. Group-oriented incentive programs were no more effective than individual-oriented programs. (Funded by the National Institutes of Health and CVS Caremark; ClinicalTrials.gov number, NCT01526265.).

Figure 1

Assessment for Eligibility and Randomization.

Figure 2. Acceptance Rates of Financial-Incentive Structures

Acceptance rates were adjusted for two stratifying variables: whether participants received their health insurance through CVS Caremark and whether their annual household income was at least $60,000 or less than $60,000. I bars denote 95% confidence intervals. In parentheses, the numerator indicates the number of participants accepting each intervention, and the denominator indicates the number of participants assigned to each intervention. The usual-care group is not shown, because there was no option to decline usual care.

Figure 3. Rates of Sustained Abstinence from Smoking at 6 and 12 Months after Target Quit Date

The primary outcome was sustained abstinence through 6 months. Asterisks indicate P values (* for P<0.05, ** for P<0.01, and *** for P<0.001) for the comparison of the four intervention groups to usual care, with adjustment for the two stratifying variables: whether participants received their health insurance through CVS Caremark and whether their annual household income was at least $60,000 or less than $60,000. I bars indicate 95% confidence intervals.