Reach and Effectiveness of a Weight Loss Intervention in Patients With Prediabetes in Colorado

INTRODUCTION Although lifestyle interventions are effective in delaying the onset of diabetes, translating these lessons to routine health care settings remains a challenge. We investigated the effectiveness of a theory-based, brief, small-group weight loss intervention for diabetes prevention. A secondary purpose was to determine the potential reach of the intervention. METHODS A total of 14,379 members of an integrated health care organization newly diagnosed with prediabetes were potentially eligible to participate in this matched cohort longitudinal study. Of this group, 1,030 attended a 90-minute, small-group session that targeted personal action planning for healthful eating, physical activity, and weight management. We accessed electronic medical records to select 1 to 2 controls (matched on impaired fasting glucose measurement, sex, age, and body mass index) for each member who attended the small-group session (n = 760). Weight change, as recorded in the medical record, was the primary outcome. Mixed models analyses were used to adjust for matching variables and covariates and to account for individual random effects over time. RESULTS Small-group participants lost significantly more weight than did their matched controls. A significantly higher proportion of small-group participants lost at least 5% of their body weight compared with controls. CONCLUSION A brief, small-group weight loss intervention was effective. However, it did not reach broadly into the population that was at risk for diabetes.