REPORTING SOURCE BIAS IN ESTIMATING PREVALENCE OF COGNITIVE IMPAIRMENT

Reporting source bias was examined using cognitive data from a probabi lity sample of adult day health care (ADHC) clients. Data were obtaine d from four sources: client, family, staff, and chart. These data sugg est that prevalence estimates are influenced by the reporting source a nd method of assessment, with chart diagnoses yielding the least conve rgent estimates. Examination of agreement summary statistics and bias indices show that both staff and family underreport prevalence of cogn itive impairment, but that more bias is associated with staff than is with family sources. Such bias should be considered in studies of prev alence estimation of cognitive impairment. Copyright (C) 1997 Elsevier Science Inc.