Validation of the relevant outcome scale for Alzheimer's disease: a novel multidomain assessment for daily medical practice

Vjera A Holthoff, Steven Ferris, Ralf Ihl, Philippe Robert, Bengt Winblad, Serge Gauthier, Kati Sternberg, Frank Tennigkeit, Vjera A Holthoff, Steven Ferris, Ralf Ihl, Philippe Robert, Bengt Winblad, Serge Gauthier, Kati Sternberg, Frank Tennigkeit

Abstract

Introduction: The Relevant Outcome Scale for Alzheimer's Disease (ROSA) is a new observer rating instrument recently developed for routine medical practice. The validity and reliability of ROSA as well as sensitivity to changes due to intervention were examined in an open-label, single-arm, multicenter clinical study in patients with Alzheimer's disease (AD).

Methods: The study enrolled 471 patients with a diagnosis of AD consistent with the criteria of the National Institute of Neurological and Communicative Disease and Stroke/Alzheimer's Disease and Related Disorders Association or with the Diagnostic and Statistical Manual Disorders criteria for dementia of Alzheimer's type. Following assessments of the ROSA and other standard assessments (Alzheimer's Disease Assessment Scale - cognitive subscale, Severe Impairment Battery, Neuropsychiatric Inventory, and Disability Assessment for Dementia), patients were treated with memantine for 12 weeks. Factor analysis of the baseline ROSA total scores was performed based on the principal components method using the varimax orthogonal rotational procedure. The psychometric analyses of the ROSA included internal consistency, test-retest reliability, inter-rater reliability, construct validity, and responsiveness to changes over time.

Results: All items showed adequate factor loadings and were retained in the final ROSA as Factor 1 (all items related to cognition, communication, function, quality of life and caregiver burden) and Factor 2 (all behavior items). The ROSA demonstrated high internal consistency (Cronbach's α = 0.93), test-retest reliability (intraclass correlation coefficient = 0.93), and inter-rater reliability (intraclass correlation coefficient = 0.91). The correlation coefficients between the ROSA and each of the validated scales ranged between 0.4 and 0.7, confirming the ROSA construct validity. Nonsubstantial floor and ceiling effects were found in middle and late disease stages, whereas a small ceiling effect was observed in the early stage. The ROSA responsiveness to change was high (responsiveness index ≥0.8) for all severity stages.

Conclusions: The ROSA is a valid and reliable instrument to aid medical practitioners in sensitively assessing AD-relevant symptoms over time in their clinical practice.

Figures

Figure 1
Figure 1
Test-retest reliability. Correlation between the Relevant Outcome Scale for Alzheimer's Disease (ROSA) total scores at screening and baseline. ICC, intraclass correlation coefficient.
Figure 2
Figure 2
Distribution of ROSA total scores at baseline in early, middle, and late disease stages. ROSA, Relevant Outcome Scale for Alzheimer's Disease.

References

    1. Robert P, Ferris P, Gauthier S, Ihl R, Winblad B, Tennigkeit F. Review of Alzheimer's disease scales: is there a need for a new multi-domain scale for therapy evaluation in medical practice? Alzheimer's Res Ther. 2010;2:24. doi: 10.1186/alzrt48.
    1. Reisberg B, Ferris SH, Leon MJ, Crook T. The global deterioration scale for assessment of primary degenerative dementia. Am J Psychiatr. 1982;139:1136–1139.
    1. 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. doi: 10.1192/bjp.140.6.566.
    1. Reisberg B. Functional assessment staging (FAST) Psychopharmacol Bull. 1988;24:653–659.
    1. Folstein MF, Folstein SE, McHugh PR. Mini-Mental State: a practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res. 1975;12:189–198. doi: 10.1016/0022-3956(75)90026-6.
    1. Rosen WG, Mohs RC, Davis KL. A new rating scale for Alzheimer's disease. Am J Psychiatr. 1984;141:1356–1364.
    1. Saxton J, Swihart AA. Neuropsychological assessment of the severely impaired elderly patient. Clin Geriatr Med. 1989;5:531–543.
    1. Cummings JL, Mega M, Gray K, Rosenberg-Thompson S, Carusi DA, Gornbein J. The Neuropsychiatric Inventory: comprehensive assessment of psychopathology in dementia. Neurology. 1994;44:2308–2314.
    1. Gélinas I, Gauthier L, McIntyre M, Gauthier S. Development of a functional measure for persons with Alzheimer's disease: the disability assessment for dementia. Am J Occup Ther. 1999;53:471–481.
    1. Bland JM, Altman DG. Cronbach's alpha. Br Med J. 1997;314:572.
    1. Guyatt G, Walter S, Norman G. Measuring change over time: assessing the usefulness of evaluative instruments. J Chron Dis. 1987;40:171–178. doi: 10.1016/0021-9681(87)90069-5.
    1. Cohen J. Statistical Power Analysis for the Behavioral Sciences. 2. Hillsdale, NJ: Laurence Erlbaum Associates; 1988.
    1. Rockwood K, Gauthier S. Trial Design and Outcomes in Dementia Therapeutic Research. London: Taylor & Francis Group; 2006.
    1. Guidelines on Medicinal Products for the Treatment of Alzheimer's Disease and Other Dementias: European Medicines Agency.
    1. Black R, Greenberg B, Ryan JM, Posner H, Seeburger J, Amatniek J, Resnick M, Mohs R, Miller DS, Saumier D, Carrillo MC, Stern Y. Scales as outcome measures for Alzheimer's disease. Alzheimer's & Dementia. 2009;5:324–339. doi: 10.1016/j.jalz.2009.05.667.
    1. Vogel A, Bhattacharya S, Waldorff FB, Waldemar G. Proxy-rated quality of life in Alzheimer's disease: a three-year longitudinal study. Int Psychogeriatr. 2011;28:1–8.
    1. Thomas SJ, Grossberg GT. Memantine: a review of studies into its safety and efficacy in treating Alzheimer's disease and other dementias. Clin Interv Aging. 2009;4:367–377.

Source: PubMed

スポンサーと協力者

医学的状態

薬物療法

3
購読する