A randomized comparative effectiveness trial for preventing type 2 diabetes

Objectives. We evaluated the weight loss effectiveness of a YMCA model for the Diabetes Prevention Program (DPP) lifestyle intervention. Methods. Between July 2008 and November 2010, we individually randomized 509 overweight or obese, low-income, nondiabetic adults with elevated blood glucose in Indianapolis, Indiana, to receive standard care plus brief lifestyle counseling or be offered a group-based YMCA adaptation of the DPP (YDPP). Primary outcome was mean weight loss difference at 12 months. In our intention-to-treat analyses, we used longitudinal linear or logistic regression, multiply imputing missing observations. We used instrumental variables regression to estimate weight loss effectiveness among participants completing 9 or more intervention lessons. Results. In the YDPP arm, 161 (62.6%) participants attended ≥ 1 lesson and 103 (40.0%) completed 9 or more lessons. In intention-to-treat analysis, mean 12-month weight loss was 2.3 kilograms (95% confidence interval [CI] = 1.1, 3.4 kg) more for the YDPP arm than for standard care participants. In instrumental variable analyses, persons attending 9 or more lessons had a 5.3-kilogram (95% CI = 2.8, 7.9 kg) greater weight loss than did those with standard care alone. Conclusions. The YMCA model for DPP delivery achieves meaningful weight loss at 12 months among low-income adults.