Kenneth Rockwood1, Sherri Fay, Mary Gorman. 1. Division of Geriatric Medicine, Capital District Health Authority, Dalhousie University, Halifax, NS, Canada. Kenneth.Rockwood@Dal.ca
Abstract
BACKGROUND: A minimum 4-point change at 6 months on the Alzheimer's disease assessment scale-cognitive subscale (ADAS-cog) is deemed clinically important, but this cut-point has been little studied in relation to clinical meaningfulness. In an investigator-initiated, clinical trial of galantamine, we investigated the extent to which a 4-point change classifies goal attainment by individual patients. METHODS: Secondary analysis of the video imaging synthesis of treating Alzheimer's disease (VISTA) study: a 4-month, multi-centre, parallel-group, double-blind, placebo-controlled, trial of galantamine in 130 mild-moderate Alzheimer's disease patients (4-month open-label follow-up). ADAS-cog responses at 6 months were compared with outcomes on three clinical measures: clinician's interview based impression of change-plus caregiver input (CIBIC+), patient/carer-goal attainment scaling (PGAS) and clinician-GAS (CGAS). RESULTS: Thirty-seven of 99 patients improved by > or = 4 points on the ADAS-cog at 6 months, and 16/99 showed > or = 4-point worsening. ADAS-cog change scores correlated notionally to modestly with changes on the CGAS (r = -0.31), the PGAS (r = -0.29) and the CIBIC+ (r = 0.31). As a group, patients with ADAS-cog improvement were significantly more likely to improve on the clinical measures; those who worsened showed non-significant clinical decline. Individually, about half were misclassified in relation to each clinical measure; often when the ADAS-Cog detected 'no change', clinically meaningful effects could be detected. Even so, no ADAS-Cog cut-point optimally classified patients' clinical responses. CONCLUSION: A 4-point ADAS-cog change at 6 months is clinically meaningful for groups. Substantial individual misclassification between the ADAS-cog and clinical measures suggests no inherent meaning to a 4-point ADAS-cog change for a given patient.
RCT Entities:
BACKGROUND: A minimum 4-point change at 6 months on the Alzheimer's disease assessment scale-cognitive subscale (ADAS-cog) is deemed clinically important, but this cut-point has been little studied in relation to clinical meaningfulness. In an investigator-initiated, clinical trial of galantamine, we investigated the extent to which a 4-point change classifies goal attainment by individual patients. METHODS: Secondary analysis of the video imaging synthesis of treating Alzheimer's disease (VISTA) study: a 4-month, multi-centre, parallel-group, double-blind, placebo-controlled, trial of galantamine in 130 mild-moderate Alzheimer's diseasepatients (4-month open-label follow-up). ADAS-cog responses at 6 months were compared with outcomes on three clinical measures: clinician's interview based impression of change-plus caregiver input (CIBIC+), patient/carer-goal attainment scaling (PGAS) and clinician-GAS (CGAS). RESULTS: Thirty-seven of 99 patients improved by > or = 4 points on the ADAS-cog at 6 months, and 16/99 showed > or = 4-point worsening. ADAS-cog change scores correlated notionally to modestly with changes on the CGAS (r = -0.31), the PGAS (r = -0.29) and the CIBIC+ (r = 0.31). As a group, patients with ADAS-cog improvement were significantly more likely to improve on the clinical measures; those who worsened showed non-significant clinical decline. Individually, about half were misclassified in relation to each clinical measure; often when the ADAS-Cog detected 'no change', clinically meaningful effects could be detected. Even so, no ADAS-Cog cut-point optimally classified patients' clinical responses. CONCLUSION: A 4-point ADAS-cog change at 6 months is clinically meaningful for groups. Substantial individual misclassification between the ADAS-cog and clinical measures suggests no inherent meaning to a 4-point ADAS-cog change for a given patient.
Authors: Charlotte M W Gaasterland; Marijke C Jansen-van der Weide; Stephanie S Weinreich; Johanna H van der Lee Journal: BMC Med Res Methodol Date: 2016-08-17 Impact factor: 4.615
Authors: Adam L Boxer; Michael Gold; Howard Feldman; Bradley F Boeve; Susan L-J Dickinson; Howard Fillit; Carole Ho; Robert Paul; Rodney Pearlman; Margaret Sutherland; Ajay Verma; Stephen P Arneric; Brian M Alexander; Bradford C Dickerson; Earl Ray Dorsey; Murray Grossman; Edward D Huey; Michael C Irizarry; William J Marks; Mario Masellis; Frances McFarland; Debra Niehoff; Chiadi U Onyike; Sabrina Paganoni; Michael A Panzara; Kenneth Rockwood; Jonathan D Rohrer; Howard Rosen; Robert N Schuck; Holly D Soares; Nadine Tatton Journal: Alzheimers Dement Date: 2020-01-06 Impact factor: 21.566