The association between functional disability and acute care utilization among the elderly in Taiwan.

Disability is associated with increased long-term care use among the elderly, but its association with utilization of acute care is not well understood. The aim of this study is to investigate the association between functional disability and acute medical care utilization among the elderly. This nationwide, population-based cohort study was based on data from the 2005 National Health Interview Survey (NHIS), linking to the 2004-2007 National Health Insurance (NHI) claims data. A total of 1521 elderly subjects aged 65 years or above were observed from the year 2004 to 2006; this sample was considered to be a national representative sample. The utilization of acute medical care (including outpatient services, emergency services, and inpatient services) and medical expenditure were measured. Functional disability was measured by determining limitations on activities of daily living (ADLs), instrumental activities of daily living (IADLs), and mobility. After adjusting for age, comorbidity, and sociodemographic characteristics, functional disability that affected IADLs or mobility was a significant factor contributing to the increased use of care. A clear proportional relationship existed between disability and utilization, and this pattern persisted across different types of acute care services. Disability affecting IADLs or mobility, rather than ADLs, was a more sensitive predictor of acute medical care utilization. Compared to elderly persons with no limitations, the medical expenditure of those with moderate-to-severe limitations was 2-3 times higher for outpatient, emergency, and inpatient services. In conclusion, functional disability among the elderly is a significant factor contributing to the increased use of acute care services.