Premium
Evaluating the clinical relevance of a cognitive composite outcome measure: An analysis of 1414 participants from the 5‐year GuidAge Alzheimer's prevention trial
Author(s) -
Coley Nicola,
Gallini Adeline,
Ousset PierreJean,
Vellas Bruno,
Andrieu Sandrine
Publication year - 2016
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2016.06.002
Subject(s) - dementia , verbal fluency test , observational study , medicine , cognition , clinical trial , clinical significance , placebo , psychology , clinical psychology , neuropsychology , physical therapy , disease , psychiatry , pathology , alternative medicine
Composite cognitive scores have been developed as primary outcome measures for preclinical/prevention trials for Alzheimer's disease (AD), mainly using observational data and with little consideration of clinical relevance. Methods Secondary analysis of placebo group data from a 5‐year AD prevention trial. The composite score was the average of the following z scores: MMSE orientation items, Free and Cued Selective Reminding Test, Category Fluency, Trail Making Test—part B. Results Composite score change from baseline differed significantly by age, APOE genotype, and CDR progression and AD dementia status. A 1 point decrease in baseline score was highly predictive of 5‐year AD dementia risk (HR = 3.51, 95% CI, 2.62–4.71, P < .001). The 1 year minimum clinically important difference was estimated at −0.3 points and predicted AD dementia. Discussion We explored the clinical relevance of a composite score in a prevention trial setting. This type of analysis facilitates the interpretation of composite scores and informs power calculations.