The Impact of Assistive Device Use on Disability Measurement

National estimates of persons with disability are of great importance since they inform policy and program development. However, accurate estimation depends on accurate measurement, and disability measurement is still evolving. Using data from the 1994–1995 National Health Interview Survey and Disability Supplement, this study examines the relationship between functional and activity limitations and equipment use in order to characterize the influence of environmental factors on disability measurement. Our findings highlight the challenging methodologic issues related to measuring a concept of disability that reflects person–environment interactions.