Vol. 27, No. 4, 2009
Issue release date: April 2009
Free Access
Dement Geriatr Cogn Disord 2009;27:344–352
Original Research Article
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Agreement in Cognitive and Clinical Assessments in Alzheimer’s Disease

Tractenberg R.E.a, b · Aisen P.S.b
aDepartments of Neurology, Biostatistics, Bioinformatics and Biomathematics, and Psychiatry, Georgetown University School of Medicine, Washington, D.C., and bDepartment of Neurology, University of California, San Diego, La Jolla, Calif., USA
email Corresponding Author

 goto top of outline Key Words

  • Alzheimer’s disease
  • Dementia
  • Outcomes assessment methods

 goto top of outline Abstract

Aims: To estimate agreement among scores on three common assessments of cognitive function. Method: Baseline responses on the Alzheimer’s Disease Assessment Scale – Cognitive, Clinical Dementia Rating, and the Mini-Mental State Examination were obtained from two clinical trials (n = 138 and n = 351). A graphical method of examining agreement, the means-difference or Bland-Altman plot, was followed by Levene’s test of the equality of variance corrected for multiple comparison within each sample. Results: 70–78% of variability was shared by one factor, suggesting that all three instruments reflect cognitive impairment. However, agreement among tests was significantly worse for individuals with greater-than-average, relative to individuals with less-than-average, cognitive impairment. Conclusions: Worse agreement between tests, as a function of increasing cognitive impairment, implies that interpretation of these tests and selection of coprimary cognitive impairment outcomes may depend on impairment level.

Copyright © 2009 S. Karger AG, Basel

 goto top of outline References
  1. Tractenberg RE, Weiner MF, Cummings JL, Thal LJ: Independence of changes in behavior from changes in cognition and function in persons with Alzheimer’s disease: a factor-analytic approach. J Neuropsychiatry Clin Neurosci 2005;17:51–60.
  2. Meulen EF, Schmand B, van Campen JP, de Koning SJ, Ponds RW, Scheltens P, Verhey FR: The seven minute screen: a neurocognitive screening test highly sensitive to various types of dementia. J Neurol Neurosurg Psychiatry 2004;75:700–705.
  3. Hughes CP, Berg L, Danziger WL, Coben LA, Martin RL: A new clinical scale for the staging of dementia. Br J Psychiatry 1982;140:566–572.
  4. Morris JC: The Clinical Dementia Rating (CDR): current version and scoring rules. Neurology 1993;43:2412–2414.
  5. Mohs RC, Rosen WG, Davis KL: The Alzheimer’s Disease Assessment Scale (ADAS): an instrument for assessing treatment efficacy. Psychopharmacol Bull 1983;18:448–450.
  6. Folstein M, Folstein S, McHugh P: ‘Mini-Mental State’: a practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res 1975;12:189–198.
  7. Leber PD: Guidelines for the Clinical Evaluation of Antidementia Drugs, First Draft. Rockville, US Food and Drug Administration, 1990.
  8. Streiner DL, Norman GR: Health Measurement Scales: a Practical Guide to Their Development and Use, ed 3. London, Oxford Medical Publications, 2003.
  9. Nunnally JC, Bernstein IH: Psychometric Theory, ed 3. New York, McGraw-Hill, 1994, p 120.
  10. Stevens J: Applied Multivariate Statistics for the Social Sciences, ed 3. Mahwah, Lawrence Erlbaum, 1996.
  11. Altman DG, Bland JM: Measurement in medicine: the analysis of method comparison studies. Statistician 1983;32:307–317.

    External Resources

  12. Oldham PD: Measurement in Medicine: the Interpretation of Numerical Data. London, English Universities Publishers, 1968, pp 150–151, 198–202.
  13. Bland JM, Altman DG: Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1986;1:307–310.
  14. Rosen WG, Mohs RC, Davis KL: A new rating scale for Alzheimer’s disease. Am J Psychiatry 1984;141:1356–1364.
  15. Thal LJ: Development of the Alzheimer’s Disease Cooperative Study. Int J Geriatr Psychopharmacol 1997;1:6–9.
  16. Aisen PS, Davis KL, Berg JD, Schafer K, Campbell K, Thomas RG, Weiner MF, Farlow MR, Sano M, Grundman M, Thal LJ: A randomized controlled trial of prednisone in Alzheimer’s disease. Alzheimer’s Disease Cooperative Study. Neurology 2000;54:588–593.
  17. McKhann G, Drachman D, Folstein M, et al: Clinical diagnosis of Alzheimer’s disease: report of the NINCDS-ADRDA Work Group under the auspices of the Department of Health and Human Services Task Force on Alzheimer’s disease. Neurology 1984;34:939–944.
  18. Aisen PS, Schafer KA, Grundman M, Pfeiffer E, Sano M, Davis KL, Farlow MR, Jin S, Thomas RG, Thal LJ; Alzheimer’s Disease Cooperative Study: Effects of rofecoxib or naproxen vs. placebo on Alzheimer disease progression: a randomized controlled trial. JAMA 2003;289:2819–2826.
  19. Tractenberg RE, Aisen PS, Weiner MF, Cummings JL, Hancock GR: Independent contributions of neural and ‘higher order’ deficits to symptoms in Alzheimer’s disease: a latent variable modeling approach. Alzheimers Dement 2006;2:303–313.

    External Resources

  20. Comrey AL, Lee HB: A First Course in Factor Analysis, ed 3. Hillsdale, Lawrence Erlbaum, 1992, p 243.
  21. Velicer WF: Determining the number of components from the matrix of partial correlations. Psychometrika 1976;41:321–327.

    External Resources

  22. O’Connor BP: SPSS and SAS programs for determining the number of components using parallel analysis and Velicer’s MAP test. Behav Res Methods Instrum Comput 2000;32:396–402.
  23. Larsen RJ, Marx ML: An Introduction to Mathematical Statistics and Its Applications, ed 2. Englewood Cliffs, Prentice Hall, 1986.
  24. Loehlin JC: Latent Variable Models: An Introduction to Factor, Path, and Structural Equation Analysis, ed 4. Mahwah, Lawrence Erlbaum, 2004.
  25. Sheskin DJ: Handbook of Parametric and Nonparametric Statistical Procedures, ed 3. Boca Raton, Chapman & Hall/CRC, 2004.
  26. Spearman C: The Abilities of Man: Their Nature and Measurement. New York, Macmillan, 1927 (reprinted: New York, AMS Publishers, 1981).
  27. Farias ST, Mungas D, Reed BR, Cahn-Weiner D, Jagust W, Baynes K, Decarli C: The measurement of everyday cognition (ECog): scale development and psychometric properties. Neuropsychology 2008;22:531–544.
  28. Crane PK, Narasimhalu K, Gibbons LE, Mungas DM, Haneuse S, Larson EB, Kuller L, Hall K, van Belle G: Item response theory facilitated cocalibrating cognitive tests and reduced bias in estimated rates of decline. J Clin Epidemiol 2008;61:1018–1027.
  29. Bland JM, Altman DG: Measuring agreement in method comparison studies. Stat Methods Med Res 1999;8:135–160.
  30. Morris JC, Edland S, Clark C, Galasko D, Koss E, Mohs R, van Belle G, Fillenbaum G, Heyman A: The consortium to establish a registry for Alzheimer’s disease (CERAD). 4. Rates of cognitive change in the longitudinal assessment of probable Alzheimer’s disease. Neurology 1993;43:2457–2465.
  31. Mungas D, Reed BR: Application of item response theory for development of a global functioning measure of dementia with linear measurement properties. Stat Med 2000;19:1631–1644.
  32. Crane PK, Narasimhalu K, Gibbons LE, Mungas DM, Haneuse S, Larson EB, Kuller L, Hall K, van Belle G: Item response theory facilitated cocalibrating cognitive tests and reduced bias in estimated rates of decline. J Clin Epidemiol 2008;61:1018–1027.

 goto top of outline Author Contacts

Rochelle E. Tractenberg
Georgetown University School of Medicine
Collaborative for Research on Outcomes and -Metrics
Building D, Suite 207, 4000 Reservoir Rd. NW, Washington, DC 20057 (USA)
Tel. +1 202 444 8748, Fax +1 202 444 4114, E-Mail ret7@georgetown.edu

 goto top of outline Article Information

Accepted: October 20, 2008
Published online: March 17, 2009
Number of Print Pages : 9
Number of Figures : 3, Number of Tables : 1, Number of References : 32

 goto top of outline Publication Details

Dementia and Geriatric Cognitive Disorders

Vol. 27, No. 4, Year 2009 (Cover Date: April 2009)

Journal Editor: Chan-Palay V. (New York, N.Y.)
ISSN: 1420-8008 (Print), eISSN: 1421-9824 (Online)

For additional information: http://www.karger.com/DEM

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