Factors associated with inconsistent diagnosis of dementia between physicians and neuropsychologists

OBJECTIVE: To explore reasons for discrepancy in the diagnosis of cognitive impairment between physicians and neuropsychologists. DESIGN: Retrospective analysis of national survey data. SETTING: Canadian Study of Health and Aging Phase 1, a national survey of c ommunity-dwelling and institutionalized older Canadians. PARTICIPANTS: 1879 subjects who completed all components of a clinical exam ination. MEASUREMENTS: Data available to both disciplines (demographic data, functio nal status, Modified Mini-Mental State (3MS), schedule H of the Cambridge M ental Disorders of the Elderly Examination (CAMDEX)), results of the physic ian's history and physical examination, and results of a psychometric test battery. Subjects were classified as No Cognitive Impairment, Cognitive Imp airment Not Dementia (CIND), and Dementia, the latter according to the crit eria of the Diagnostic and Statistical Manual, 3rd Ed., Revised. Preliminar y diagnoses by physicians and neuropsychologists were compared. RESULTS: In univariate modeling, higher education increased consistency. Lo wer scores on the 3MS, depression reported in the CAMDEX, focal neurologica l signs, and all neuropsychological variables decreased agreement. In multi variate modeling, higher education and identification of longterm memory im pairment by the neuropsychologist increased agreement; lower scores on the 3MS, depression reported on the CAMDEX, and identification of short-term me mory impairment or constructional impairment led to disagreement. When the category of CIND was removed, kappa for agreement increased from 0.51 to 0. 92.