[영문]Purpose: This study systematically reviews approaches that national surveys have used to measure the use of assistive devices and examines the implications of these different approaches for prevalence estimates of device use and disability in late life. Design and Methods: Cross-sectional data from six national surveys are used to compare rates of assistive device use and disability among community-dwelling adults aged 65 and older. Results: Estimates of the use of any device are similar across surveys, ranging from 14% to 18% for the population of adults aged 65 and older. However, one survey design element?the restriction of device-use questions to those reporting difficulty with daily activities?omits a potentially sizeable group: those who use devices but report no difficulty. Including this group of device users significantly increases the prevalence estimates of both device use and disability. Implications: The use of assistance and perceptions of difficulty are inextricably interwoven, and attention to the measurement of these concepts is needed. Survey designers may want to consider asking questions about assistive device use independent of questions about difficulty. In addition, researchers who study disability may want to consider including those who report using devices but no difficulty, a group that may become more prevalent as new cohorts age.