Article type: Research Article
Authors: Trenkle, Douglas L.a; * | Shankle, William R.b; c | Azen, Stanley P.d
Affiliations: [a] Maine Coast Memorial Hospital, Ellsworth, ME, USA | [b] Medical Care Corporation, Irvine, CA, USA | [c] Department of Cognitive Sciences, University of California, Irvine, CA, USA | [d] Department of Preventive Medicine, Keck School of Medicine, University of Southern California, CA, USA
Correspondence:
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Corresponding author: Douglas L. Trenkle, D.O., Maine Coast Memorial Hospital, 50 Union Street, Ellsworth, ME 04605, USA. Tel.: +1 207 664 5722; Fax: +1 207 664 5490; E-mail: [email protected].
Abstract: Early detection of Alzheimer's disease and related disorders (ADRD) is important, especially in primary care settings. We compared performances of two common screening tests, the Mini-Mental State Exam (MMSE) and Clock Drawing Test (CDT), with that of the MCI Screen ({MCIS}) in 254 patients over 65. None had previous diagnosis of ADRD, and 81% were asymptomatic by Functional Assessment Staging Test ({FAST}) (FAST=1). 215 patients completed all screening tests – 141 had ⩾ 1 abnormal result, 121/141 completed standardized diagnostic assessment, and the remaining 74/215 (34%) screened entirely normally and weren't further evaluated. Potential bias due to unevaluated cases was statistically adjusted. Among diagnosed cases: AD=43%, cerebrovascular disease=36%, other causes=21%. Bias-adjusted MCI prevalence for FAST stages 1 and 1–3 were 13.9–20.3% and 23.0–28.3%. Bias-adjusted results for the CDT, MMSE and MCIS were: clinical diagnosis validity (kappa statistic)={−0.02 (p=0.61), 0.06 (p=0.23), 0.92 (p< 0.0001)}; sensitivity={59%, 71%, 94%}; specificity={39%, 36%, 97%}; overall accuracy={54%, 62%, 96%}; positive predictive value={16%, 17%, 86%}; and negative predictive value={83%, 87%, 96%}. The MMSE and CDT were not valid for early detection, while the MCIS had high validity and accuracy in the primary care cohort.
Keywords: Normal aging, mild cognitive impairment, Alzheimer's disease, prevalence, sensitivity, accuracy, early detection, primary care, receiver operating characteristic, validity
DOI: 10.3233/JAD-2007-11309
Journal: Journal of Alzheimer's Disease, vol. 11, no. 3, pp. 323-335, 2007
