Background and Aim
Nearly 7 in 10 adults in the United States are overweight or obese. Two-thirds of large US employers offer financial incentives to their employees to promote healthy behaviors such as weight loss. One financial incentive strategy is the use of deposit or pre-commitment contracts. Deposit contracts are voluntary arrangements in which people who want to achieve a goal (eg, a weight loss goal) put some of their own money at risk that they stand to lose if they do not meet their goal. This approach aims to augment motivation by leveraging loss aversion, a powerful behavioral economic principle in which people are more affected by losses than an equivalent dollar gain.
The purpose of this study was to test in a workplace setting and through an automated platform the degree to which differing levels of employer matching of employee deposits increase rates of participation in deposit contracts, characterize the corresponding amount of weight loss, and identify factors associated with non-participation in these programs.
Intervention and Design
The study conducted a 36-week parallel design randomized trial (24 intervention weeks plus 12 weeks of follow-up) at Horizon Healthcare Services, Inc, between May 24, 2011, and March 15, 2012. The 132 participants were randomly assigned to a control group or to 1 of the 3 deposit contract groups, all of which were given the same goal of losing 1 pound per week for 24 weeks. Weights were measured at baseline, 4, 8, 12, 16, 20, 24, and 36 weeks using incentaHEALTH workplace scales that provided precision to 0.2 pounds. All participants had access to a secure website to track their progress and were asked to complete online questionnaires at baseline, 24, and 36 weeks.
Interventions - Control arm participants were provided with a link to the Weight-control Information Network and were reminded to attend monthly weigh-ins on the workplace scales. After each weigh-in, participants were notified whether they met or did not meet their weight loss goal. Participants in each of the 3 deposit contract arms received the information that control arm participants received. In addition, at the start of each intervention month, participants in a deposit contract arm needed to make a deposit of their own money for the upcoming month. Participants could choose to deposit between $1 per day and $3 per day for the next 28 days. For each day in that month that participants weighed in and were at or below their goal weight, the funds they had chosen to deposit for that day were returned at the end of the month as a reward, with a match corresponding to group assignment.
Main Outcomes and Measures - The primary outcome measure was weight loss after 24 weeks. The main secondary outcome measure was participation in deposit contracts. Other secondary outcomes included weight loss at 36 weeks (ie, 12 weeks after deposit contract opportunities ended) and changes in potential mediators of weight loss such as physical activity, eating behaviors, and participation in weight-related wellness programs from baseline to primary outcome measurement at 24 weeks.
Way to Health Use
Study Enrollment and Block Stratification Randomization: Enroll participants across all study arms through block stratification randomization
Messaging: Automated messaging to participants via email or text-message
Device Integration: Collect weight data from participants
Deposit Contracts: Collect deposits from participants
Findings and Conclusions
Among participants eligible to make deposits, 29% made ≥1 deposit and matching did not increase participation. At 24 weeks, control participants gained an average of 1.0 pound, whereas 1:1 match participants lost an average of 5.3 pounds (P = .005). After 36 weeks, control participants gained an average of 2.1 pounds, whereas no match participants lost an average of 5.1 pounds (P = .008).
Participation in deposit contracts to promote weight loss was low, and matching deposits did not increase participation. For deposit contracts to impact population health, ongoing participation will need to be higher.