Cross-sectional and longitudinal assessments of function in prodromal-to-mild Alzheimer's disease: A comparison of the ADCS-ADL and A-IADL-Q scales.

Abstract

Prior observational work in a heterogeneous cohort of participants with mild cognitive impairment suggests the Amsterdam Instrumental Activities of Daily Living Questionnaire (A-IADL-Q) may have greater sensitivity for functional decline than the more established Alzheimer's Disease Cooperative Study-Activities of Daily Living (ADCS-ADL) scale. However, the relative utility of the A-IADL-Q versus the ADCS-ADL for clinical trials in early Alzheimer's disease (AD) remains uncertain. We compared baseline and longitudinal performance of the A-IADL-Q and ADCS-ADL in participants with biomarker-confirmed prodromal (pAD; n=158) or mild (mAD; n=283) AD enrolled in the 18-month Tauriel study of semorinemab (NCT03289143). The A-IADL-Q exhibited numerically stronger discrimination between pAD and mAD participants at baseline per Cohen's d analyses and similar sensitivity to longitudinal decline across cohorts over 18 months relative to the ADCS-ADL. The comparable performance of the ADCS-ADL and A-IADL-Q supports the utility of the A-IADL-Q in early AD clinical trials. The Amsterdam Instrumental Activities of Daily Living Questionnaire (A-IADL-Q) may be more sensitive than the Alzheimer's Disease Cooperative Study-Activities of Daily Living Scale (ADCS-ADL) for distinguishing prodromal and mild Alzheimer's disease (AD).A-IADL-Q and ADCS-ADL are similarly sensitive to decline in early AD over 18 months.Comparable performance of these indices supports A-IADL-Q use in future AD trials.Additional AD clinical trial data could extend findings across more diverse cohorts.