Excess body weight increases the burden of age-associated chronic diseases and their associated health care expenditures

Abstract

Aging and excessive adiposity are both associated with an increased risk of developing multiple chronic diseases, which drive ever increasing health costs. The main aim of this study was to determine the net (non-estimated) health costs of excessive adiposity and associated age-related chronic diseases. We used a prevalence-based approach that combines accurate data from the Health Search CSD-LPD, an observational dataset with patient records collected by Italian general practitioners and up-to-date health care expenditures data from the SiSSI Project. In this very large study, 557,145 men and women older than 18 years were observed at different points in time between 2004 and 2010. The proportion of younger and older adults reporting no chronic disease decreased with increasing BMI. After adjustment for age, sex, geographic residence, and GPs heterogeneity, a strong J-shaped association was found between BMI and total health care costs, more pronounced in middle-aged and older adults. Relative to normal weight, in the 45-64 age group, the per-capita total cost was 10% higher in overweight individuals, and 27 to 68% greater in patients with obesity and very severe obesity, respectively. The association between BMI and diabetes, hypertension and cardiovascular disease largely explained these elevated costs.

Keywords: body mass index; cardiovascular disease; cost analysis; diabetes; disease burden; hypertension; obesity.

Figure 1. Total (a) and outpatient (b) health care expenditure

Decomposition of differences in health care expenditure (direct, indirect and overall costs) by age group and BMI category compared to normal‐weight individuals (euro per year) for outpatient (b) and total (a) health expenditure. Note: - Indirect marginal effects for each BMI category were computed as the sum of nonlinear combinations of parameters estimated within each pathology‐specific equation with the respective pathology‐specific parameter estimated within the health expenditure equation. ‐ Direct marginal effects for each BMI category were obtained as relative parameter estimates from the health expenditure equation. ‐Overall marginal effects for each BMI category was computed as the sum of the respective direct and indirect marginal effects.

Figure 2. Total (a) and outpatient (b) indirect health care expenditure

Decomposition of indirect health care expenditure by pathology, age group and BMI category compared to normo‐weight individuals (euro per year) for outpatient (b) and total (a) health expenditure. Note: Pathology specific indirect marginal effects for each BMI category were computed as the nonlinear combinations of parameters estimated within each pathology‐specific equation with the respective pathology‐specific parameter estimated within the health expenditure equation.