Research ArticleCommitment Contracts and Team Incentives: A Randomized Controlled Trial for Smoking Cessation in Thailand
Introduction
Treatment for tobacco dependence is not widely available in low-resource settings in the developed and developing world. Standard treatment options—nicotine replacement therapy, prescription drugs, and professional counseling—are efficacious,1, 2, 3 but are not presently feasible in many areas, where trained health professionals are scarce, access to and availability of health services is limited, and treatment is relatively expensive. This study tests a novel intervention that uses social and monetary incentives for delivering smoking-cessation services to rural communities in central Thailand.
This study assesses the potential of voluntary, binding financial agreements to promote smoking abstinence. Behavioral economists have recently applied these commitment contracts to health behaviors such as weight loss, exercise, and smoking cessation.4, 5, 6 In the most rigorous study of smoking-cessation contracts to date, smokers in the Philippines CARES trial deposited money with study staff that was returned at 6 months conditional on quitting. Smoking abstinence at 12 months increased 3.5% points (38%) for depositors compared to a control group that received a pamphlet about quitting.7 Yet, 66% of depositors forfeited their contributions.
The present study aims to strengthen commitment contracts by supplementing monetary commitment with a form of social commitment. Specifically, the study induces peer pressure by offering a pair of smokers (a team) a cash bonus contingent on both people quitting. Peer pressure is a strong force for increasing willpower and motivation.8, 9, 10 Buddy interventions that rely on social support are a common adjunct to smoking treatment, but have not consistently enhanced the likelihood of quitting.11, 12 Likewise, cash incentives for quitting often fail to induce lasting quits.13 In the present study, however, participants deposit money up front, selecting for smokers who have a desire to be abstinent rather than those who are only financially motivated. In sum, all participants received group counseling, and those in the intervention group were also offered regular text message reminders and multiple incentives contingent on quitting at 3 months: a small up-front contribution with the option to make additional deposits, a project-matched contribution, and a large team incentive. The combination of reminders and monetary and social incentives is hypothesized to help smokers to quit successfully.
Thailand is an appropriate study setting for two reasons. First, all Thai villages have a network of community health workers (CHWs). The workers served as recruiters and deposit collectors but did not require technical training. Many experts believe that CHWs can help alleviate the health workforce shortage in rural areas.14, 15 Second, Thailand has a high demand for quitting,16 due in part to its comprehensive tobacco control policies,17 and commitment contracts rely on smokers having a pre-existing desire to quit. Global tobacco control efforts are expected to spur an increased demand for quitting in the coming decade, which will make low-cost treatment options in the developing world increasingly important.
Section snippets
Study Site and Participants
This study employs a randomized design undertaken in six subdistricts of Nakhon Nayok province, located 125 km northeast of Bangkok. The villages lie within the catchment area of the province’s major tertiary hospital, where the research team was based. The enumeration area includes 42 villages, each with about 500 residents. The region is agrarian and has a median household income of $10 per day.18 Prior to recruitment, CHWs were paid to conduct a census of smokers in their village, in order
Data Analysis
The primary outcome is biochemically verified abstinence at 6 months. Secondary outcome measures include study participation, biochemically verified smoking status at 3 months, and self-reported smoking status at 14 months. Trial participation is an indicator of the feasibility of and demand for the intervention. The difference between smoking status at 3 and 6 months is an indicator of relapse following the intervention. The analysis also includes calculations of the incremental cost per
Results
Figure 1 shows the trial profile. According to the household census, 2055 smokers lived in the 42 study communities, although only 86.6% of CHWs returned data-collection forms. The trial enrolled 215 smokers, a participation rate of 10.5% among census takers. Adjusting for random nonreporting in the census (=2055/0.866), the participation rate in the study area is 9.1%, although this likely understates participation, as smokers not counted in the census were not likely invited to join the
Discussion
The team commitment intervention increased the likelihood of quitting among adult smokers living in rural communities of central Thailand by 91%–136% relative to the control group, according to biochemically verified results at 6 months. Few studies have assessed smoking-cessation interventions targeted to rural populations in the developing world, despite the large share of their deaths attributable to tobacco use. The effectiveness of the behavioral intervention is on par with
Acknowledgments
The authors thank Parichart Sukanthamala for outstanding field assistance and Tawima Sirirassamee and Chaturon Tangsangwornthamma for advice while in the field. All errors are our own. The full study protocol is available from the corresponding author.
The study was funded by grants from the U.S. National Institute on Aging (P30-AG012839, T32-AG000246) and the U.S. National Institute for Child Health and Development (R21-HD056581). The study’s sponsors had no role in study design, data
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2020, SSM - Population HealthCitation Excerpt :In theory, such interventions may encourage individuals to modify their behavior by eliciting emotional or material support from friends, family members or co-workers, or by appealing to accountability, fear of social punishment, or shame. These intervention approaches may take a variety of forms, ranging from group therapy, to one-on-one cessation support, to team-based incentive designs in which rewards or penalties are contingent upon the behaviors of a group of smokers (Faseru et al., 2018; Stead et al., 2017; White et al., 2013). These team-based incentive designs may be particularly successful by leveraging peer pressure or peer support (Haisley et al., 2012; Kullgren et al., 2013; Patel et al., 2016) or by encouraging social interactions between teammates that result in individuals exerting more effort to achieve their goals (Babcock 2019).
Trial registration: This study is registered at ClinicalTrials.gov NCT01311115.