Predictors of weight loss in overweight veterans with knee osteoarthritis who participated in a clinical trial.

Individuals with osteoarthritis (OA) of the knee have a high prevalence of obesity. The objective of this study was to determine predictors of weight loss among participants with knee OA in a clinical trial. A secondary analysis of data from a randomized clinical trial was used. Multiple regression analysis was used to predict weight loss after identification of predictor variables from the data. Hypothesized predictors of weight loss included demographic, clinical, and behavioral characteristics. The only baseline variable that was significantly related to weight loss was the Center for Epidemiologic Studies Depression Scale (CES-D) score. The CES-D score was an independent predictor of weight loss at 16 (p < 0.01) and 32 weeks (p < 0.05). Receiving nutrition counseling was also predictive of weight loss at 16 weeks (p < 0.03). These two variables explained 24% and 22% of the variance in weight loss for weeks 16 and 32, respectively. Being less depressed and receiving nutritional counseling appeared predictive of weight loss in this group of veterans.