Way to Health

CHOP Weight Loss

Test Effectiveness of two financial incentive designs for promoting weight loss among obese employees

Apr 22, 2014

Jeffrey Kullgren, MD, MS, MPH Jeffrey Kullgren, MD, MS, MPH
Andrea B. Troxel, ScD Andrea B. Troxel, ScD

Background and Aim

Most adults in the United States are overweight or obese, a public health challenge associated with increased mortality and higher costs for employers, private payers, and public health insurance programs. There has been limited success in alleviating the problem. Consequently there is broad interest in new approaches to combat obesity and change behaviors that contribute to it.

One approach that has shown promise in promoting healthy behaviors is the use of financial incentives. An estimated 67% of large employers are using these strategies in the hopes of decreasing the incidence of chronic disease and slowing the growth of health care costs. This study looked at the effectiveness of two financial incentive designs for promoting weight loss among obese employees.

Intervention and Design

They conducted a 36-week parallel design randomized, controlled trial between March 17,2011 and January 21, 2012. One hundred and five participants gave their informed consent, were given the goal of losing 1 pound per week for 24 weeks, and were randomly assigned to a monthly weigh-in control group or 1 of 2 monthly financial incentive groups. Weights were measured using incentaHEALTHâ„¢ workplace scales that provided precision to 0.2 pounds. All participants had access to a secure website to track their individual progress and complete questionnaires. The protocol was approved by the institutional review board of the University of Pennsylvania.

Interventions - Participants were randomized to the 3 study arms using 1:1:1 central computerized randomization with a block size of 15. 24 weeks of monthly weigh-ins (control)(n=35); individual incentive, designed as $100 per person per month for meeting or exceeding target weight loss (individual arm)(n=35); group incentive, designed as $500 per month split between any participant within groups of 5 who met or exceeded their target weight loss (group arm)(n=35).

Main Outcomes and Measures - Weight loss after 24 weeks (primary outcome); weight loss after 36 weeks, changes in behavioral mediators of weight loss (secondary outcomes). They also conducted exploratory analyses of weight loss goal attainment by month.

Way to Health Use

Findings and Conclusion

Group incentive participants lost more weight than individual arm participants (between-group difference in weight loss favoring group = mean 9.7 pounds, 95% CI 4.4 to 14.9; P < 0.001). Twelve weeks after incentives ended and adjusting for 3-group comparisons, group arm participants maintained greater weight loss than control arm participants (between-group difference in weight loss = mean 6.5 pounds, 95% CI 1.2 to 11.7; P = 0.016) but not more than individual arm participants (difference = 5.9 pounds, 95% CI, 0.8 to 11.0; P = 0.024).

A group-based financial incentive was more effective than an individual incentive and monthly weigh-ins at promoting weight loss among obese employees at 24 weeks.

Publications and Press

  • Individual vs. Group-Based Incentives for Weight Loss: A Randomized, Controlled Trial
  • The Role of Behavioral Economic Incentive Design and Demographic Characteristics in Financial Incentive-Based Approaches to Changing Health Behaviors: A Meta-Analysis