Examining Ways to Improve Weight Control Programs' Population Reach and Representativeness: A Discrete Choice Experiment of Financial Incentives.

Background: Both theoretical and empirical evidence supports the potential of modest financial incentives to increase the reach of evidence-based weight control programs. However, few studies exist that examine the best incentive design for achieving the highest reach and representativeness at the lowest cost and whether or not incentive designs may be valued differentially by subgroups that experience obesity-related health disparities.

Methods: A discrete choice experiment was conducted (n = 1232 participants; over 90% of them were overweight/obese) to collect stated preference towards different financial incentive attributes, including reward amount, program location, reward contingency, and payment form and frequency. Mixed logit and conditional logit models were used to determine overall and subgroup preference ranking of attributes. Using the National Health and Nutrition Examination Survey data sample weights and the estimated models, we predicted US nationally representative participation rates by subgroups and examined the effect of offering more than one incentive design. External validity was checked by using a completed cluster randomized control trial.

Results: There were significant subgroup differences in preference toward incentive attributes. There was also a sizable negative response to larger incentive amounts among African Americans, suggesting that higher amounts would reduce participation from this population. We also find that offering participants a menu of incentive designs to choose from would increase reach more than offering higher reward amounts.

Conclusions: We confirmed the existence of preference heterogeneity and the importance of subgroup-targeted incentive designs in any evidence-based weight control program to maximize population reach and reduce health disparities.