The iADRS as an integrated measure of cognition and function: Psychometric evidence from recent clinical trials in early symptomatic Alzheimer's disease

Findings confirm integrated Alzheimer's Disease Rating Scale (iADRS) total score reliability, validity, and sensitivity. Using the Rasch Measurement Theory (RMT), iADRS item set shows improved reliability relative to its component subscales. iADRS item thresholds are well distributed along the disease severity continuum. iADRS shows sensitivity to concurrent progression of cognitive and functional impairment. Crosswalk tables provide direct translation between iADRS, Clinical Dementia Rating - Sum of Boxes (CDR-SB), and Mini-Mental State Examination (MMSE).