Skip to main content Accessibility help

Improving the Accuracy and Precision of Cognitive Testing in Mild Dementia

  • Hans Wouters (a1) (a2), Bregje Appels (a3), Wiesje M. van der Flier (a4), Jos van Campen (a5), Martin Klein (a6), Aeilko H. Zwinderman (a1), Ben Schmand (a7) (a8), Willem A. van Gool (a7), Philip Scheltens (a4) and Robert Lindeboom (a1)...


The CAMCOG, ADAS-cog, and MMSE, designed to grade global cognitive ability in dementia have inadequate precision and accuracy in distinguishing mild dementia from normal ageing. Adding neuropsychological tests to their scale might improve precision and accuracy in mild dementia. We, therefore, pooled neuropsychological test-batteries from two memory clinics (ns = 135 and 186) with CAMCOG data from a population study and 2 memory clinics (n = 829) and ADAS-cog data from 3 randomized controlled trials (n = 713) to estimate a common dimension of global cognitive ability using Rasch analysis. Item difficulties and individuals’ global cognitive ability levels were estimated. Difficulties of 57 items (of 64) could be validly estimated. Neuropsychological tests were more difficult than the CAMCOG, ADAS-cog, and MMSE items. Most neuropsychological tests had difficulties in the ability range of normal ageing to mild dementia. Higher than average ability levels were more precisely measured when neuropsychological tests were added to the MMSE than when these were measured with the MMSE alone. Diagnostic accuracy in mild dementia was consistently better after adding neuropsychological tests to the MMSE. We conclude that extending dementia specific instruments with neuropsychological tests improves measurement precision and accuracy of cognitive impairment in mild dementia. (JINS, 2012, 18, 314–322)


Corresponding author

Correspondence and reprint requests to: Hans Wouters, Department of Pharmacoepidemiology and Clinical Pharmacology, Faculty of Science, Utrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht University, 3584 CG, Utrecht, The Netherlands. E-mail:


Hide All
American Psychiatric Association. (1987). Diagnostic and statistical manual of mental disorders, revised third edition. Washington, DC: Author.
De Jager, C.A., Milwain, E., Budge, M. (2002). Early detection of isolated memory deficits in the elderly: The need for more sensitive neuropsychological tests. Psychological Medicine, 32, 483491.
Fischer, G.H., Molenaar, I.W. (1995). Rasch models: Foundations, recent developments and applications. New York: Springer-Verlag.
Folstein, M.F., Folstein, S.E., McHugh, P.R. (1975). “Mini-mental state”. A practical method for grading the cognitive state of patients for the clinician. Journal of Psychiatric Research, 12, 189198.
Frankfort, S.V., Appels, B.A., De Boer, A., Tulner, L.R., Van Campen, J.P., Koks, C.H., Beijnen, J.H. (2006). Treatment effects of rivastigmine on cognition, performance of daily living activities and behaviour in Alzheimer's disease in an outpatient geriatric setting. International Journal of Clinical Practice, 60, 646654.
Harrison, J., Minassian, S.L., Jenkins, L., Black, R.S., Koller, M., Grundman, M. (2007). A neuropsychological test battery for use in Alzheimer disease clinical trials. Archives of Neurology, 64, 13231329.
Hobart, J.C., Cano, S.J., Zajicek, J.P., Thompson, A.J. (2007). Rating scales as outcome measures for clinical trials in neurology: Problems, solutions, and recommendations. Lancet Neurology, 6, 10941105.
Holman, R., Lindeboom, R., Glas, C.A.W., Vermeulen, M., De Haan, R.J. (2003). Constructing an item bank using Item Response Theory: The AMC linear disability score project. Health Services and Outcomes Research Methodology, 4, 1933.
Jenkinson, C., Fitzpatrick, R., Garratt, A., Peto, V., Stewart-Brown, S. (2001). Can item response theory reduce patient burden when measuring health status in neurological disorders? Results from Rasch analysis of the SF-36 physical functioning scale (PF-10). Journal of Neurology, Neurosurgery, and Psychiatry, 71, 220224.
Jonker, C., Schmand, B., Lindeboom, J., Havekes, L.M., Launer, L.J. (1998). Association between apolipoprotein E epsilon4 and the rate of cognitive decline in community-dwelling elderly individuals with and without dementia. Archives of Neurology, 55, 10651069.
Kelderman, H. (1988). Common item equating: Using the loglinear Rasch model. Journal of Educational Statistics, 13, 319336.
Lezak, M.D. (1995). Neuropsychological assessment. New York: Oxford University Press.
Lindeboom, J., Schmand, B., Tulner, L., Walstra, G., Jonker, C. (2002). Visual association test to detect early dementia of the Alzheimer type. Journal of Neurology, Neurosurgery, and Psychiatry, 73, 126133.
McKeith, I.G., Galasko, D., Kosaka, K., Perry, E.K., Dickson, D.W., Hansen, L.A., Perry, R.H. (1996). Consensus guidelines for the clinical and pathologic diagnosis of dementia with Lewy bodies (DLB): Report of the consortium on DLB international workshop. Neurology, 47, 11131124 .
McKhann, G., Drachman, D., Folstein, M., Katzman, R., Price, D., Stadlan, E.M. (1984). Clinical diagnosis of Alzheimer's disease: Report of the NINCDS-ADRDA Work Group under the auspices of Department of Health and Human Services Task Force on Alzheimer's Disease. Neurology, 34, 939944.
Meulen, E.F., Schmand, B., Van Campen, J.P., De Koning, S.J., Ponds, R.W., Scheltens, P., Verhey, F.R. (2004). The seven minute screen: A neurocognitive screening test highly sensitive to various types of dementia. Journal of Neurology, Neurosurgery, and Psychiatry, 75, 700705.
Mohs, R.C., Knopman, D., Petersen, R.C., Ferris, S.H., Ernesto, C., Grundman, M., Thal, L.J. (1997). Development of cognitive instruments for use in clinical trials of antidementia drugs: Additions to the Alzheimer's Disease Assessment Scale that broaden its scope. The Alzheimer's Disease Cooperative Study. Alzheimer's Disease and Associated Disorders, 11(Suppl. 2), S13S21 .
Mungas, D., Reed, B.R., Kramer, J.H. (2003). Psychometrically matched measures of global cognition, memory, and executive function for assessment of cognitive decline in older persons. Neuropsychology, 17, 380392.
Neary, D., Snowden, J.S., Gustafson, L., Passant, U., Stuss, D., Black, S., Benson, D.F. (1998). Frontotemporal lobar degeneration: A consensus on clinical diagnostic criteria. Neurology, 51, 15461554 .
Raskind, M.A., Peskind, E.R., Wessel, T., Yuan, W. (2000). Galantamine in AD: A 6-month randomized, placebo-controlled trial with a 6-month extension. The Galantamine USA-1 Study Group. Neurology, 54, 22612268.
Reitan, R.M. (1955). The relation of the trail making test to organic brain damage. Journal of Consulting Psychology, 19, 393394.
Román, G.C., Tatemichi, T.K., Erkinjuntti, T., Cummings, J.L., Masdeu, J.C., Garcia, J.H., Hofman, A. (1993). Vascular dementia: Diagnostic criteria for research studies. Report of the NINDS-AIREN International Workshop. Neurology, 43, 250260 .
Rosen, W.G., Mohs, R.C., Davis, K.L. (1984). A new rating scale for Alzheimer's disease. American Journal of Psychiatry, 141, 13561364.
Roth, M., Tym, E., Mountjoy, C.Q., Huppert, F.A., Hendrie, H., Verma, S., Goddard, R. (1986). CAMDEX. A standardized instrument for the diagnosis of mental disorder in the elderly with special reference to the early detection of dementia. British Journal of Psychiatry, 149, 698709.
Stroop, J.R. (1935). Studies of interference in serial verbal reactions. Journal of Experimental Psychology, 18, 643662.
Tariot, P.N., Solomon, P.R., Morris, J.C., Kershaw, P., Lilienfeld, S., Ding, C. (2000). A 5-month, randomized, placebo-controlled trial of galantamine in AD. The Galantamine USA-10 Study Group. Neurology, 54, 22692276.
Tombaugh, T.N., McIntyre, N.J. (1992). The mini-mental state examination: A comprehensive review. Journal of the American Geriatrics Society, 40, 922935.
Van der Vlies, A.E., Pijnenburg, Y.A., Koene, T., Klein, M., Kok, A., Scheltens, P., van der Flier, W.M. (2007). Cognitive impairment in Alzheimer's disease is modified by APOE genotype. Dementia and Geriatric Cognitive Disorders, 24, 98103.
Vellas, B., Andrieu, S., Sampaio, C., Coley, N., Wilcock, G. (2008). Endpoints for trials in Alzheimer's disease: A European task force consensus. Lancet Neurology, 7, 436450.
Verhelst, N.D., Glas, C.A.W. (1995). The one parameter logistic model. In G.H. Fischer & I.W. Molenaar (Eds.), Rasch models, foundations, recent developments and applications (pp. 215237) New York: Springer Verlag.
Walstra, G.J., Teunisse, S., Van Gool, W.A., Van Crevel, H. (1997). Reversible dementia in elderly patients referred to a memory clinic. Journal of Neurology, 244, 1722.
Wechsler, D. (1991). Wechsler intelligence scale for children — third edition (WISC - III). San Antonio: The Psychological Corporation.
Wechsler, D. (1997). Wechsler adult intelligence scale - III. San Antonio: The Psychological Corporation.
Wilcock, G.K., Lilienfeld, S., Gaens, E. (2000). Efficacy and safety of galantamine in patients with mild to moderate Alzheimer's disease: Multicentre randomized controlled trial. Galantamine International-1 Study Group. British Medical Journal, 321, 17.
Wouters, H., Van Gool, W.A., Schmand, B., Lindeboom, R. (2008). Revising the ADAS-cog for a More Accurate Assessment of Cognitive Impairment. Alzheimer's Disease and Associated Disorders, 22, 236244.
Wouters, H., Van Gool, W.A., Schmand, B., Zwinderman, A.H., Lindeboom, R. (2009). Three sides of the same coin: Measuring global cognitive impairment with the MMSE, ADAS-cog and CAMCOG. International Journal of Geriatric Psychiatry, 25, 770779.



Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed