Physical activity is associated with many health benefits including reduced rates of cardiovascular disease, diabetes, hypertension, and obesity. However, more than 50% of adults in the United States do not achieve enough regular physical activity to obtain these benefits. More than 85% of large employers use financial incentives for health promotion including programs to increase physical activity. Often lottery-based financial incentives are used. However, the best way to design these incentives to increase physical activity had not been well examined.
We designed a 6-month randomized controlled trial to test different ways of designing lottery-based financial incentives to increase physical activity. We partnered with the University of Pennsylvania Human Resources Department and enrolled 209 overweight and obese employees. All participants used their smartphones to track activity and were randomly assigned to a control group or one of three different lottery-based designs with similar expected value.
We found that the two-tiered lottery, which had a higher chance of winning a smaller amount of $5 and a lower chance of winning a higher amount of $50, was the most effective with participants achieving physical activity goals - 38% of the time compared to 26% in the control (P=0.01). A Jackpot lottery with a very small chance of $500 was no different than the control. A basic lottery with a higher chance of winning $5 was also no different than the control.
University of Pennsylvania Human Resources Department
National Institute on Aging (NIA), NIH