Differences between questionnaire- and interview-based measures of activities of daily living (ADL) ability and their association with observed ADL ability in women with rheumatoid arthritis, knee osteoarthritis, and fibromyalgia

Although self-report based on questionnaire is the common method to obtain information about activities of daily living (ADL) ability in rheumatic diseases, little is known about the relationship between measures of ADL ability based on questionnaire, interview, and observation. The present study examined whether measures of self-reported ADL ability based on questionnaire and interview yielded different results, determined whether the magnitude of the difference varied among women with rheumatoid arthritis (RA), knee osteoarthritis (OA), and fibromyalgia (FM), and investigated the relationships between self-reported and observed ADL ability.