International Psychogeriatrics

Table of Contents - 2006 - Volume 18, Issue 02  


The validity of brief screening cognitive instruments in the diagnosis of cognitive impairment and dementia after first-ever stroke

Velandai Srikanth a1c1, Amanda G. Thrift a2, Jayne L. Fryer a1, Michael M. Saling a3, Helen M. Dewey a2, Jonathan W. Sturm a4 and Geoffrey A. Donnan a2
a1 Menzies Research Institute, Hobart, Australia
a2 National Stroke Research Institute, Repatriation Campus, Austin Health, Victoria, Australia
a3 Department of Psychology, University of Melbourne, Parkville, Melbourne, Victoria, Australia
a4 Department of Neurology, Gosford Hospital, NSW, Australia

Article author query
srikanth v   [PubMed][Google Scholar] 
thrift ag   [PubMed][Google Scholar] 
fryer jl   [PubMed][Google Scholar] 
saling mm   [PubMed][Google Scholar] 
dewey hm   [PubMed][Google Scholar] 
sturm jw   [PubMed][Google Scholar] 
donnan ga   [PubMed][Google Scholar] 

Abstract

Introduction: Brief cognitive tests such as the Mini-mental State Examination (MMSE) and the Informant Questionnaire for Cognitive Decline in the Elderly (IQCODE) have been used to detect cognitive impairment and dementia in studies of stroke patients. However, there are few data on their validity for such use. We have evaluated their validity in detecting cognitive impairment not dementia (CIND) and dementia in a community-based sample of first-ever stroke patients.

Methods: The standardized MMSE (S-MMSE) and the 16-item IQCODE were administered to 79 patients 1 year after a first-ever stroke. CIND and dementia were diagnosed independently using a comprehensive cognitive battery. The performances of the two tests were evaluated using receiver operating characteristic (ROC) analyses. Combined performance was evaluated when their scores were used in parallel (the “or rule”), in series (the “and rule”) or as a weighted sum (the “weighted sum rule”).

Results: Both tests were extremely poor at detecting CIND individually and in combination. For dementia, at traditional cut-points, the S-MMSE ([less-than-or-equal]23) was insensitive (0.50, 95% CI 0.16–0.84) and the IQCODE ([greater-than-or-equal]3.30) nonspecific (0.63, 95% CI 0.51–0.75). An acceptable balance between sensitivity and specificity was achieved for dementia using the “or rule” combination, but with only modest positive predictive value.

Conclusions: The S-MMSE and the IQCODE were individually poor at detecting CIND and dementia after a nonaphasic first-ever stroke. The combination was useful in detecting dementia but it does not replace the need for detailed neuropsychological tests.

(Received April 26 2005)
(returned for revision May 30 2005)
(revised version received June 27 2005)
(Accepted June 28 2005)
(Published Online January 6 2006)


Key Words: stroke; cognition; dementia; screening tests; validity.

Correspondence:
c1 Correspondence should be addressed to: Dr. Velandai Srikanth, Menzies Research Institute, 17 Liverpool St, Hobart, Australia 7001. Phone: +61 3 62267700; Fax: +61 3 62267704. Email: velandai.srikanth@utas.edu.au.

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