Changes in the Association Between Body Mass Index and Medicare Costs, 1997-2006

Abstract

The rising prevalence of overweight and obesity at older ages is projected to result in escalating Medicare spending.^1,2 Although prior research on excess Medicare costs associated with overweight and obesity has assumed that these costs are similar over time, the health effects of excess weight may be changing, with significant implications for health care costs. For example, mortality associated with obesity has declined,³ while the association between obesity and disability has increased.⁴ It is unclear how changes in the health of the obese population have affected obesity-associated health care costs. Available evidence is conflicting^5,6 and is based on estimated expenditures from the Medical Expenditure Panel Surveys (MEPS), which substantially underestimates spending.⁷ Using Medicare claims data, we examined whether trends in Medicare Part A and B spending differed by body mass index (BMI) over time (1997-2006).