Weight loss and lifetime medical expenditures: a case study with TRICARE prime beneficiaries.

Background: TRICARE's Prime (managed care) plan spends more than $1 billion annually in medical expenditures attributed to overweight and obesity.

Purpose: This study estimates change in lifetime disease prevalence and medical expenditures associated with weight loss for beneficiaries in TRICARE's Prime plan.

Methods: This 2010 analysis uses Markov Chain Monte Carlo simulation with demographics, biometrics, health behavior, and disease presence for 857,200 overweight and 521,800 obese beneficiaries aged 18-64 years in 2008 to model future onset of diseases linked to excess weight. Prediction equations in the simulation come from multiple sources: (1) regression analysis with longitudinal (2007-2008) TRICARE medical claims and electronic health records for 2.1 million beneficiaries; (2) regression analysis with Medical Expenditure Panel Survey (2002-2007) and National Health and Nutrition Examination Survey (1999-2008) data; (3) cancer and mortality risk from Surveillance, Epidemiology, and End Results data; and (4) published findings from clinical trials.

Results: Among overweight and obese beneficiaries, lifetime medical expenditures declined $440 (3% discount rate) for each permanent 1% reduction in body weight. This includes $590 in savings from improved health, offset by $150 in additional expenditures from prolonged life. Estimates range from $660 reduction for grossly obese adults aged <45 years to $40 gain from grossly obese adults aged 55-64 years (where expenditures from increased longevity exceed savings from improved health). If weight loss is temporary and regained after 24 months, lifetime expenditures decline by $40 per 1% reduction in body weight.

Conclusions: Long-term benefits from weight loss are substantially greater than short-term benefits, underscoring the need for a societal perspective to combat obesity.