The clock drawing test in primary care: sensitivity in dementia detection and specificity against normal and depressed elderly

Objectives The aim of this study was to examine the sensitivities and speci ficities of the clock drawing test (CDT) in the detection of dementia among older people in primary care, with particular emphasis on the effect of de pression on CDT specificity. Most previous studies have been sited in speci alist settings and few have addressed the issue of specificity aginst depre ssion. Methods Comparison of cohorts identified from community-based screening wit h GMS-AGECAT. The CDT and the Mini-Mental State Examination (MMSE) were adm inistered to 41 elderly subjects with organic disorder (dementia), 84 elder ly subjects with case level depression and 523 normal elderly subjects. Sen sitivities and specificities of the CDT were calculated. Results The sensitivity of the CDT in the detection of dementia in the gene ral community was 76%. The specificities of the CDT against normal elderly and depressed elderly was 81% and 77% respectively. Higher sensitivity and specificity were achieved by the MMSE. Conclusions The use of the CDT in the detection of dementia syndromes is li kely to be more relevant in the primary care context than in specialist set tings. The CDT provides good sensitivity and specificity but may not be as sensitive or specific in the general community as previous studies have sug gested, particularly in mild dementia. Community-based late life. depressio n does not appear to alter the specificity of the CDT. Copyright (C) 2001 J ohn Wiley & Sons, Ltd.