Health services use and health care costs of obese and nonobese individuals

Background: Obesity has clinical and economic consequences. Few studies have compared health care resource utilization between age- and sex-matched obese and nonobese persons. Methods: We conducted a retrospective study in obese and nonobese individuals matched by age, sex, medical clinic, and selected exclusionary diagnoses. Data collected included hospitalizations, outpatient visits, professional claims, and prescriptions over 1 year. Costs were assigned to medical resources based on market prices using publicly available costs. Comorbid conditions were determined using a chronic disease score (CDS) index. Groups were compared on types and costs of resources consumed. Regression models were used to examine the effect of body mass index (BMI) on costs while controlling for age and chronic diseases. Results: A total of 539 obese and 1225 nonobese persons were examined. Obese patients had more hospitalizations (P<.001), prescription drugs (P<.001), professional claims (P<.001), and outpatient visits (P=.005). Obese patients used more cardiovascular, intranasal allergic rhinitis, asthma, ulcer, diabetes, thyroid, and analgesic drugs. Total costs between groups were different (median of $585.44 for obese and $333.24 for nonobese patients; P<.001). Cost differences were primarily due to medications (P<.001). Predictors of total costs were age, sex, BMI, and CDS. For each unit BMI increase, costs increased 2.3% (P<.001). For each CDS unit increase, costs increased 52.9% (P<.001). Conclusion: Over I year, health care costs for obese persons are higher than for nonobese persons, primarily because of prescription drugs.