Purpose: To evaluate the effect of financial incentive in a diabetes prevention weight loss program at worksites.
Design: Group-level randomized intervention study.
Setting: Four long-term care facilities, randomly assigned to "incentive-IG" or "non incentive-NIG" groups.
Participants: Ninety-nine employees, all overweight or obese (BMI= mean 34.8±7.4 kg/m2) and at risk for type 2 diabetes.
Intervention: A 16 week weight loss program (diabetes prevention program) with a 3 month follow up. IG could either choose a "standard incentive" to receive cash award when achieving the projected weight loss or to participate in a "standard plus deposit incentive" to get additional money matched with their deposit for projected weight loss. All of the participants received a one-hour consultation for a healthy weight loss at the beginning.
Measures: Weight-loss, diabetes risk score (DRS), and cardiovascular risk outcomes.
Analyses: Linear and logistic regressions for completed cases with adjustments for clustering effect at group level.
Results: IG lost on average more pounds (p=0.027), reduced BMI (p=0.04), and reduced in DRS (p=0.011) compared to NIG at week 16. At the 12-week follow-up period, those in IG plus deposit subgroup had twice the odds (OR=2.2, p=0.042) and those in the standard IG had three times the odds of achieving weight loss goals than NIG; those in the IG plus deposit group reduced DRS by 0.4 (p=0.045).
Conclusion: Monetary incentives appear to be effective in reducing weight and diabetes risk.
Keywords: Health promotion; diabetes; health behavior; incentive; obesity.