Use of the Clock-Drawing Test to screen for dementia in primary care

Archives of Clinical Neuropsychology, 1996

International Psychogeriatrics, 2008

Clock-drawing tests are popular components of dementia screens but no single scoring system has been universally accepted. We sought to identify an optimal subset of clock errors for dementia screening and compare them with three other systems representative of the existing wide variations in approach (Shulman, Mendez, Wolf-Klein), as well as with the CDT system used in the Mini-Cog, which combines clock drawing with delayed recall. The clock drawings of an ethnolinguistically and educationally diverse sample (N = 536) were analyzed for the association of 24 different errors with the presence and severity of dementia defined by independent research criteria. The final sample included 364 subjects with > or = 5 years of education, as preliminary examination suggested different error patterns in subjects with 0-4 years of education and inadequate numbers of normal controls for reliable analysis. Eleven of 24 errors were significantly associated with dementia in subjects with > or = 5 years of education, and six were combined to identify dementia with 88% specificity and 71% sensitivity: inaccurate time setting, no hands, missing numbers, number substitutions or repetitions, or refusal to attempt clock drawing. Time setting was the most prevalent error at all dementia stages, refusal occurred only in moderate and severe dementia; and ethnicity and language of administration had no effect. All critical errors increased in frequency with dementia stage. This simplified scoring system had much better specificity than two other systems (88% vs 39% for Mendez's system - 63% for Shulman's) and much better sensitivity than Wolf-Klein's (71% vs 51%). Stepwise logistic regression found the simplified system to be more strongly predictive of dementia than the three other CDT systems of dementia. Substituting the new CDT algorithm for that used in the original CDT Mini-Cog improved the Mini-Cog's specificity from 89 to 93% with minimal change in sensitivity. Only six errors need be assessed to capture most of the power of clock drawing to discriminate between people with dementia and normal subjects, and improves specificity over older systems in subjects with > or = 5 years of education. These errors require minimal conceptual classification and are easily detected and scored by non-specialists.

Dementia and Geriatric Cognitive Disorders, 2011

Archives of Gerontology and Geriatrics, 2009

Journal of clinical and diagnostic research : JCDR, 2013

An early and a quick identification of dementia is desirable to improve the overall care to the affected persons in the developing countries. The aim of this study was to evaluate the discriminative abilities of the Mini Mental State Examination (MMSE) and the Clock Drawing Test (CDT) in differentiating the demented patients from the controls and also the differentiation between the different types of dementia. This study was designed to evaluate the patients with varied types and severities of dementia, who were diagnosed by using the Clinical Dementia Rating (CDR) scale. All the patients completed the MMSE and the simplified CDT. This study included 197 patients with an age range of 43-79 years. Fifty-one patients (25.9%) were diagnosed with Alzheimer Dementia (AD), 37 patients (18.8%) with Vascular Dementia (VD), 23 patients (11.7%) with Parkinson's Disease Dementia (PDD) and 86 patients (43.6%) with other variants of dementia. The total MMSE score of the enrolled patients wa...

The Journals of Gerontology Series A: Biological Sciences and Medical Sciences, 1999

Disproportionate increases in dementia morbidity in ethnic minorities challenge established screening methodologies because of language and culture barriers, varying access to health services, and a relative paucity 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 minority elders. The effectiveness of the Clock Drawing Test (CDT) for dementia detection was compared with that of the Mini-Mental State Examination (MMSE) and the Cognitive Abilities Screening Instrument (CASI) in community-dwelling elders of diverse linguistic, ethnic, and educational backgrounds. Subjects (N = 295) were tested at home in their native languages (English, n = 141; another language, n = 154). An informant-based clinical dementia history and functional severity index derived from the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) protocols were used to classify subjects as probably demented (n = 170), and probably not demented (n = 125). All tests were significantly affected by education (p < .001) but not by primary language (p > .05). Sensitivities and specificities for probable dementia were 82% and 92%, respectively, for the CDT; 92% and 92% for the MMSE; and 93% and 97% for the CASI for subjects completing each test. However, in poorly educated non-English speakers, the CDT detected demented subjects with higher sensitivity than the two longer instruments (sensitivity and specificity 85% and 94% for the CDT, 46% and 100% for the MMSE, and 75% and 95% for the CASI). Moreover less information was lost due to noncompletion of the CDT than the MMSE or CASI (severe dementia or refusal: CDT 8%, MMSE 12%, and CASI 16%). Overall, the CDT may be as effective as the MMSE or CASI as a first-level dementia screen for clinical use in multiethnic, multilingual samples of older adults. Its brevity (1-5 minutes), minimal language requirements, high acceptability, and lack of dependence on specialized testing materials are well adapted for screening of non-English-speaking elderly persons in settings where bilingual interpreters are not readily available and screening time is at a premium.

International Journal of Geriatric Psychiatry, 2002

SUMMARY Background Clock drawing tests (CDTs) vary in format, scoring, and complexity. Herein, we compared the dementia screening performance of seven CDT scoring systems and the judgements of untrained raters. Methods 80 clock drawings by subjects of known dementia status were selected, 20 from each of four categories (Consortium to Establish a Registry for Alzheimer's disease [CERAD] de®ned normal, mild, moderate, and severe abnormality). An expert rater scored all clocks using published criteria for seven systems. Additionally, 20 naõ Ève raters judged clocks as either normal or abnormal, without formal instructions. Clocks were then classi®ed by drawers' dementia status for comparison of dementia detection across systems. Results Naõ Ève and formal CDT systems showed 90±100% agreement in CERAD normal, moderate and severe categories, but poor agreement (mean ˆ 39%) for mildly impaired clocks. When CDT systems were compared for accurate dementia classi®cation, the Mendez a...