Association of obesity with healthcare utilization and costs in a Medicare population

Objectives: To examine the association of obesity with healthcare resource utilization and costs in a Medicare population. Methods: This study was a retrospective cohort study using Humana Medicare Advantage (MA) claims data. Body mass index (BMI) was assessed using ICD-9-CM status codes (V85 hierarchy) that have been validated in the data source to classify patients into BMI categories: normal (N), overweight (Ow), obese class I (ObI), obese class II (ObII), and obese class III (ObIII). Healthcare resource utilization (HRU) and costs were determined based on claims data. Descriptive statistics were used to examine baseline characteristics and HRU across BMI classes. Multivariable analysis was used to examine the association between BMI class and outcome measures. Results: Among the 172,866 patients aged >= 65 years that were identified, BMI distribution was: N, 21%; Ow 37%; ObI, 24%, ObII, 10%; and ObIII, 9%. Inpatient, emergency department and outpatient utilization increased with greater BMI level, and greater BMI level was associated with higher total healthcare, medical and pharmacy costs. Greater prevalence of several cardiometabolic conditions, total medication use, and use of specific medication classes was observed with increasing BMI class. Conclusions: Greater BMI was associated with greater HRU and costs and observed increase in prevalence of cardiometabolic conditions. These results reflect an urgent need to address the epidemic of obesity and the resulting excessive clinical and economic burden on the healthcare system.