SIST-M-IR activities of daily living items that best discriminate clinically normal elderly from those with mild cognitive impairment.

Abstract

Activities of daily living (ADL) impairment is a hallmark of Alzheimer's disease (AD) dementia, but impairment in instrumental ADL (IADL) has been reported in mild cognitive impairment (MCI). The Structured Interview and Scoring Tool-Massachusetts Alzheimer's Disease Research Center (MADRC)-Informant Report (SIST-MIR) includes 60 graded items that assist in scoring the Clinical Dementia Rating; it assesses the spectrum of cognitive and ADL changes relevant to early AD. Of the 60 SIST-M-IR items, 41 address IADL; we aimed to determine which of these best discriminate individuals with MCI from clinically normal (CN) elderly. We assessed 447 subjects participating in the MADRC longitudinal cohort (289 CN, 158 MCI). We performed logistic regression analyses predicting the probability of CN vs. MCI diagnosis using the SIST-M-IR items. Analyses were adjusted for demographic characteristics. We found that 4 SIST-M-IR items best discriminated between CN and MCI subjects (MCI performing worse than CN): "participating in games that involve retrieving words" (p=0.0001), "navigating to unfamiliar areas" (p=0.001), "performing mental tasks involved in a former primary job" (p=0.002), and "fixing things or finishing projects" (p=0.002). Our results point to the earliest functional changes seen in elderly at risk for AD, which could be captured by a few simple questions. Honing the sensitivity of clinical assessment tools will help clinicians differentiate those individuals with normal aging from those who are developing cognitive impairment.