biostudies-literatureUnknown67(1)Levine SZ<h4>Background</h4>A short yet reliable cognitive measure is needed that separates treatment and placebo for treatment trials for Alzheimer's disease. Hence, we aimed to shorten the <i>Alzheimer</i>'<i>s Disease Assessment Scale Cognitive Subscale</i> (ADAS-Cog) and test its use as an efficacy measure.<h4>Methods</h4>Secondary data analysis of participant-level data from five pivotal clinical trials of donepezil compared with placebo for Alzheimer's disease (N = 2,198). Across all five trials, cognition was appraised using the original 11-item ADAS-Cog. Statistical analysis consisted of sample characterization, item response theory (IRT) to identify an ADAS-Cog short version, and mixed models for repeated-measures analysis to examine the effect sizes of ADAS-Cog change on the original and short versions in the placebo versus donepezil groups.<h4>Results</h4>Based on IRT, a short ADAS-Cog was developed with seven items and two response options. The original and short ADAS-Cog correlated at baseline and at weeks 12 and 24 at 0.7. Effect sizes based on mixed modeling showed that the short and original ADAS-Cog separated placebo and donepezil comparably (ADAS-Cog original ES = 0.33, 95% CI = 0.29, 0.40, ADAS-Cog short ES = 0.25, 95% CI =0.23, 0.34).<h4>Conclusions</h4>IRT identified a short ADAS-cog version that separated donepezil and placebo, suggesting its clinical potential for assessment and treatment monitoring.European psychiatry : the journal of the Association of European Psychiatristse19https://www.ebi.ac.uk/biostudies/studies/S-EPMC10966609biostudies-literatureShortening the Alzheimer's disease assessment scale cognitive subscale.PMC10966609Levine SZSamara MIwatsubo TCipriani AGoldberg YRotstein AFurukawa TAYoshida KLeucht SfalseShortening the Alzheimer's disease assessment scale cognitive subscale.<h4>Background</h4>A short yet reliable cognitive measure is needed that separates treatment and placebo for treatment trials for Alzheimer's disease. Hence, we aimed to shorten the <i>Alzheimer</i>'<i>s Disease Assessment Scale Cognitive Subscale</i> (ADAS-Cog) and test its use as an efficacy measure.<h4>Methods</h4>Secondary data analysis of participant-level data from five pivotal clinical trials of donepezil compared with placebo for Alzheimer's disease (N = 2,198). Across all five trials, cognition was appraised using the original 11-item ADAS-Cog. Statistical analysis consisted of sample characterization, item response theory (IRT) to identify an ADAS-Cog short version, and mixed models for repeated-measures analysis to examine the effect sizes of ADAS-Cog change on the original and short versions in the placebo versus donepezil groups.<h4>Results</h4>Based on IRT, a short ADAS-Cog was developed with seven items and two response options. The original and short ADAS-Cog correlated at baseline and at weeks 12 and 24 at 0.7. Effect sizes based on mixed modeling showed that the short and original ADAS-Cog separated placebo and donepezil comparably (ADAS-Cog original ES = 0.33, 95% CI = 0.29, 0.40, ADAS-Cog short ES = 0.25, 95% CI =0.23, 0.34).<h4>Conclusions</h4>IRT identified a short ADAS-cog version that separated donepezil and placebo, suggesting its clinical potential for assessment and treatment monitoring.2024-01-01T00:00:00Z2024 Feb2025-04-04T12:24:43.359Z2025-04-04T12:24:43.359ZS-EPMC109666093838939010.1192/j.eurpsy.2024.14