The Clock Drawing Test: Utility for dementia detection in multiethnic elders

Background, Disproportionate increases in dementia morbidity in ethnic mino rities challenge established screening methodologies because of language an d culture barriers, varying access to health sen ices, and a relative pauci ty of cross-cultural data validating their use. Simple screening techniques adapted to a range of health and social service settings would accelerate dementia detection and social and health services planning for demented min ority elders. Methods. The effectiveness of the Clock Drawing Test (CDT) for dementia det ection was compared with that of the Mini-Mental State Examination (MMSE) a nd the Cognitive Abilities Screening Instrument (CASI) in community-dwellin g elders of diverse linguistic, ethnic, and educational backgrounds. Subjec ts (N = 295) were tested at home in their native languages (English, n = 14 1; another language, n = 154). An informant-based clinical dementia history and functional severity index derived from the Consortium to Establish a R egistry for Alzheimer's Disease (CERAD) protocols were used to classify sub jects as probably demented (n = 170), and probably not demented (n = 125). Results. All tests were significantly affected by education (p < .001) but not by primary language (p > .05). Sensitivities and specificities for prob able dementia were 82% and 92%, respectively, for the CDT; 92%; and 92% for the Mh ISE; and 93% and 97% for the CASI for subjects completing each test . However, in poorly educated non-English speakers, the CDT detected dement ed subjects with higher sensitivity than the two longer instruments (sensit ivity and specificity 85% and 94% for the CDT, 46% and 100% for the MMSE, a nd 75% and 95% for the CAST). Moreover less information was lost due to non completion of the CDT than the MMSE or CASI (severe dementia or refusal: CD T 8%, MMSE 12%, and CASI 16%). Conclusions. Overall, the CDT may be as effective as the MMSE or CASI as a first-level dementia screen for clinical use in multiethnic, multilingual s amples of older adults. Its brevity (1-5 minutes), minimal language require ments, high acceptability, and lack of dependence on specialized testing ma terials are well adapted for screening of non-English-speaking elderly pers ons in settings where bilingual interpreters are not readily available and screening time is at a premium.