Obesity, disease burden, and prescription spending by community-dwelling Medicare beneficiaries.

OBJECTIVES: To assess drug utilization and cost patterns by body mass index (BMI) for Medicare beneficiaries including cohorts diagnosed with diseases resulting from, or aggravated by, obesity. RESEARCH
DESIGN: We used data from the 2003 Medicare Current Beneficiary Survey to characterize the community-dwelling Medicare population by BMI class and to assess the following outcomes: (1) prevalence of drugs recommended in treating obesity-related chronic diseases, (2) annual spending on these medications by disease cohort, and (3) spending for all medications for the full study sample. Linear regression techniques were used to assess the conditional association of BMI class with drug spending controlling for sociodemographic characteristics, prescription drug coverage, health status, and comorbidities.
RESULTS: Annual drug spending in 2003 was significantly higher (p < 0.05) for obese class I ($2374) and class III ($2976) compared to normal-weight beneficiaries ($1764). Obese individuals also had higher utilization rates for selected medications used to treat diabetes, hypertension, ischemic heart disease, heart failure, hyperlipidemia, and osteoarthritis. Regression results indicate that chronic disease is the main reason why drug spending is higher among the obese, but prescription drug coverage is also a significant factor.
CONCLUSIONS: Obesity is associated with significantly higher drug spending among Medicare beneficiaries. The combination of growing numbers of obese beneficiaries, high rates of chronic disease, and greater than average prescription spending per condition will all contribute to higher future Part D and overall Medicare program costs. Limitations of the study include: self-reported data on height, weight, and drug use/spending; small sample size; and pre-Part D data.