Review of Outcome Measurement Instruments in Alzheimer's Disease Drug Trials: Psychometric Properties of Global Scales

Abstract

The use of global outcome measures with strong psychometric properties in Alzheimer's disease (AD) drug trials is encouraged. This article focuses on Clinician Global Impression of Change scales, the Clinical Dementia Rating, and the Global Deterioration Scale to provide (1) a review of psychometric properties, (2) a critique of how these properties are assessed in the literature, and (3) a basis for evaluating, from the standpoint of psychometric properties, the appropriateness of using a given global scale in a drug trial. Reported reliability and validity estimates for the aforementioned scales range from fair to very good, but small sample sizes and/or inappropriate measures of correlation weaken the quality of the evidence. There is also a dearth of published information on responsiveness to change. Researchers planning AD drug trials should consider these issues, along with the interval between test administrations for test-retest reliability, to help select appropriate global outcome measurement instruments. (J Geriatr Psychiatry Neurol 2000; 13:197-205).

Get full access to this article

View all access options for this article.

References

Wolfson C , Moride Y , Perrault A , et al. Drug treatments for Alzheimer's disease I: a comparative analysis of clinical trials. Ottawa: Canadian Coordinating Office for Health Technology Assessment, 2000.

Guy W. ECDEU assessment manual for psychopharmacology, revised. Rockville, MD: Department of Health, Education, and Welfare, 1976.

Berg L , Miller JP , Storandt M , et al. Mild senile dementia of the Alzheimer type: 2. Longitudinal assessment . Ann Neurol 1988; 23:477-484.

Reisberg B , Ferris SH , de Leon MJ , Crook T. The Global Deterioration Scale for assessment of primary degenerative dementia. Am J Psychiatry 1982; 139:1136-1139.

Meya U , Raschig A , Siegfried K , Wannenmacher W. Primary outcome measures in dementia drug trials: Modified Clinical Interview-Based Impression of Change (CIBIC-M). Int J Methods Psychiatr Res 1994; 4:189-192.

Boothby H , Mann AH , Barker A. Factors determining inter-rater agreement with rating global change in dementia: the CIBIC-plus. Int J Geriatr Psychiatry 1995 ; 10:1037-1045.

Knopman DS , Knapp MJ , Gracon SI , et al. The Clinician Interview-Based Impression (CIBI): a clinician's global change rating scale in Alzheimer's disease. Neurology 1994; 44: 2315-2321.

Schneider LS , Olin JT. Clinical global impressions in Alzheimer's clinical trials. Int Psychogeriatr 1996; 8:277-289.

Dahlke F , Lohaus A , Gutzmann H. Reliability and clinical concepts underlying global judgments in dementia: implications for clinical research. Psychopharmacol Bull 1992; 28:425-432.

10.

Korner A , Lauritzen L , Bech P. A psychometric evaluation of dementia rating scales. Eur Psychiatry 1996; 11:185-191.

11.

Claus JJ , Teunisse S , Walstra GJM , van Gool WA. Determinants of global clinical change assessment in patients with early Alzheimer's disease. Dement Geriatr Cogn Disord 1998; 9:157-163.

12.

Rogers SL , Doody RS , Mohs RC. Donepezil improves cognition and global function in Alzheimer disease, a 15-week, doubleblind, placebo-controlled study. Donepezil Study Group. Arch Intern Med 1998; 158:1021-1031.

13.

Rogers SL , Farlow MR , Doody RS , et al. A 24-week, double-blind, placebo-controlled trial of donepezil in patients with Alzheimer's disease. Donepezil Study Group. Neurology 1998; 50:136-145.

14.

Rogers SL , Freidhoff LT. The efficacy and safety of donepezil in patients with Alzheimer's disease: results of a US multicentre, randomized, double-blind, placebo-controlled trial. The Donepezil Study Group. Dementia 1996; 7:293-303.

15.

Burns A , Rossor M , Hecker J , et al. The effects of donepezil in Alzheimer's disease—results from a multinational trial. Dement Geriatr Cogn Disord 1999; 10:237-244.

16.

Streiner DL , Norman GR. Health measurement scales: a practical guide to their development and use . New York: Oxford University Press , 1989.

17.

McDowell I , Jenkinson C. Development standards for health measures . J Health Serv Res Policy 1996; 1:238-246.

18.

Hughes CP , Berg L , Danziger WL , et al. A new clinical scale for the staging of dementia. Br J Psychiatry 1982; 140:566-572.

19.

Morris JC. The Clinical Dementia Rating (CDR): current version and scoring rules. Neurology 1993; 43:2412-2414.

20.

Dooneief G , Marder K , Tang M-X , et al. The Clinical Dementia Rating Scale: community-based validation of 'profound' and 'terminal' stages. Neurology 1996; 46:1746-1749.

21.

Berg L. Clinical Dementia Rating (CDR). Psychopharmacol Bull 1988; 24:637-639.

22.

Burke WJ , Miller JP , Rubin EH , et al. Reliability of the Washington University Clinical Dementia Rating . Arch Neurol 1988; 45:31-32.

23.

Reisberg B , Schneider L , Doody R , et al. Clinical global measures of dementia. Position paper from the International Working Group on Harmonization of Dementia Drug Guidelines. Alzheimer Dis Assoc Disord 1997; 11(Suppl 3):8-18.

24.

Morris JC , Ernesto C , Schafer K , et al. Clinical Dementia Rating training and reliability in multicenter studies: the Alzheimer's Disease Cooperative Study experience. Neurology 1997; 48:1508-1510.

25.

McCulla MM , Coats M , Van Fleet N , et al. Reliability of clinical nurse specialists in the staging of dementia . Arch Neurol 1989; 46:1210-1211.

26.

Summers WK , DeBoynton V , Marsh GM , Majovski LV. Comparison of seven psychometric instruments used for evaluation of treatment effect in Alzheimer's dementia . Neuroepidemiology 1990; 9:193-207.

27.

Juva K , Sulkava R , Erkinjuntti T , et al. Staging the severity of dementia: comparison of clinical (CDR, DSM-III-R), functional (ADL, IADL) and cognitive (MMSE) scales. Acta Neurol Scand 1994; 90:293-298.

28.

Harshbarger TR. Introductory statistics: a decision map. 2nd Ed. New York: Macmillan, 1977.

29.

Fillenbaum GG , Peterson B , Morris JC. Estimating the validity of the Clinical Dementia Rating Scale: the CERAD experience . Aging Clin Exp Res 1996; 8:379-385.

30.

Morris JC , Heyman A , Mohs RC , et al. The Consortium to Establish a Registry for Alzheimer's Disease (CERAD). Part I. Clinical and neuropsychological assessment of Alzheimer's Disease. Neurology 1989; 39:1159-1165.

31.

Brodaty H , Lie D. Symptomatology: functional capacity and behaviour . In: Wimo A , Jonsson B , Karlsson G , Winblad B , eds. Health economics of dementia . New York: John Wiley & Sons , 1998:33-51.

32.

McLendon BM , Doraiswamy PM. Defining meaningful change in Alzheimer's disease trials: the donepezil experience. J Geriatr Psychiatry Neurol 1999; 12:39-48.

33.

Berg L , Miller JP , Baty J , et al. Mild senile dementia of the Alzheimer type. 4. Evaluation of intervention . Ann Neurol 1992; 31:242-249.

34.

Patterson CJS , Gauthier S , Bergman H , et al. Management of dementing disorders: conclusions from the Canadian Consensus Conference on Dementia. Can Med Assoc J 1999 ; 160(Suppl 12):S1-S15.

35.

Reisberg B , Ferris SH , de Leon MJ , Crook T. Global Deterioration Scale (GDS) . Psychopharmacol Bull 1988; 24:661-663.

36.

Reisberg B , Ferris SH , Steinberg G , et al. Longitudinal study of dementia patients and aged controls. In: Lawton MP , Herzog AR , eds. Special research methods for gerontology. Amityville, NY : Baywood, 1989:195-231.

37.

Gottlieb GL , Gur RE , Gur RC. Reliability of psychiatric scales in patients with dementia of the Alzheimer type. Am J Psychiatry 1988; 145:857-860.

38.

Foster JR , Sclan S , Welkowitz J , et al. Psychiatric assessment in medical long-term care facilities: reliability of commonly used rating scales. Int J Geriatr Psychiatry 1988; 3:229-233.

39.

Cohen-Mansfield J , Reisberg B , Bonnema J , et al. Staging methods for the assessment of dementia: perspectives . J Clin Psychiatry 1996; 57:190-198.

40.

Hartmaier SL , Sloan PD , Guess HA , Koch GG. The MDS Cognition Scale: a valid instrument for identifying and staging nursing home residents with dementia using the Minimum Data Set. JAm Geriatr Soc 1994; 42:1173-1179.

41.

Gordon JE , Powell C , Rockwood K. Goal attainment scaling as a measure of clinically important change in nursing-home patients. Age Ageing 1999; 28:275-281.

42.

Morris JC , Edland S , Clark C , et al. The Consortium to Establish a Registry for Alzheimer's Disease (CERAD). Part IV. Rates of cognitive change in the longitudinal assessment of probable Alzheimer's disease. Neurology 1993; 43:2457-2465.

43.

MacCallum RC , Widaman KF , Zhang S , Hong S. Sample size in factor analysis. Psychol Methods 1999; 4:84-99.

44.

Charter RA. Sample size requirements for precise estimates of reliability, generalizability, and validity coefficients. J Clin Exp Neuropsychol 1999; 21:559-566.

45.

Lucca U , Menasce G , Comelli M , et al. An example of a clinical trial in patients with Alzheimer's disease: some methodological issues. Prog Clin Biol Res 1989; 317:1310.

46.

Schmitt N , Gooding RZ , Nolan KA , Kirsch M. Meta-analyses of validity studies published between 1964 and 1982 and the investigation of study characteristics . Personnel Psychol 1984; 37:407-422.

47.

Salgado JF. Sample size in validity studies of personnel selection. J Occup Org Psychol 1998; 71:161-164.

48.

Cicchetti DV. Sample size requirements for increasing the precision of reliability estimates: problems and proposed solutions. J Clin Exp Neuropsychol 1999; 21:567-570.

49.

Donner A , Eliasziw M. Sample size requirements for reliability studies . Stat Med 1987; 6:441-448.

50.

Walter SD , Eliasziw M , Donner A. Sample size and optimal designs for reliability studies. Stat Med 1998; 17:101-110.

51.

Cohen J. Weighted kappa: nominal scale agreement with provision for scaled disagreement or partial credit. Psychol Bull 1968; 70:213-220.

52.

Cohen J. A coefficient of agreement for nominal scales. Educ Psychol Measure 1960; 20:37-46.

53.

Kazis LE , Anderson JJ , Meenan RF. Effect sizes for interpreting changes in health status. Med Care 1989; 27(Suppl 3): S178-S189.

54.

Norman GR. Issues in the use of change scores in randomized trials. J Clin Epidemiol 1989; 42:1097-1105.

55.

Cronbach LJ , Furby L.

How should we measure "change"— or should we?

Psychol Bull 1970; 74:68-80.

56.

Guyatt G , Walter S , Norman G. Measuring change over time: assessing the usefulness of evaluative instruments . J Chron Dis 1987; 40:171-178.

57.

MacKenzie CR , Charlson ME , DiGioia D , Kelley K. Can the sickness impact profile measure change? An example of scale assessment. J Chron Dis 1986; 39:429-438.

58.

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 Department of Health and Human Services Task Force on Alzheimer's Disease. Neurology 1984 ; 34:939-944.