The Reliability and Validity of Self-Report Activities of Daily Living Scales

Abstract

A measurement evaluation study was conducted to examine the reliability and validity of the Physical Self-Maintenance Scale and Instrumental Activities of Daily Living Scale (Lawton & Brody, 1969) as a discriminative measure to assess the independent living status of elderly hospitalized patients. A sample of thirty patients from two geriatric specialty units was used for the study. Inter-observer reliability was shown to be excellent (ADL r=.96, IADL r=.99) and test-retest reliability was considered to be good (ADL r=.59, IADL r=.93). The results comparing patient self-report of ability and ratings based on direct observation of performance indicated that patients consistently over-rated their ability in both ADL and IADL tasks. This provides support for the use of direct observation of performance to obtain valid data on an individual's ability. There was a significant difference in scores between those patients able to be discharged home compared to those requiring institutionalization; however, a score predictive of discharge location could not be identified with the study data. The study provided support for the use of this measurement tool for assessing the independent living status of elderly hospitalized patients. It provides the therapist with a measure that has had some validation and has the potential for clinical use in describing patients' ability and identifying areas requiring treatment intervention.