Measuring Functional Ability and Chronic Health Conditions among the Elderly: A Research Note on the Adequacy of Three Instruments

Abstract

The reliability and validity of 3 measures of the health of the elderly are examined: an index measuring the ability to perform the activities of daily living without help (Index of Living Skills), an index measuring functional disability (Shanas''s Index Disability) and an index measuring chronic health conditions (the index subsequently used in the U.S. Health Insurance Study). The data involve a random sample of elderly persons living in Manitoba in 1971. The analyses used, correlational matrices, factor analyses, internal consistency reliability coefficients and construct validity, are reported separately for those living in conventional housing in the community, in subsidized housing and in institutions providing some form of medical care. Evidently the Index of Living Skills measures not 1 but 2 underlying constructs (heavy and light tasks), Shanas''s Index of Disability is reliable and valid when used among those living in the community and in institutions but not among those in subsidized housing and the index of chronic conditions is relatively unreliable among all 3 groups of elderly persons.