Can a direct IADL measure detect deficits in persons with MCI?

Objective: To determine if a direct measure of instrumental activities of daily living (IADL) scale designed for use with dementia patients can detect differences between persons with mild cognitive impairment (MCI) and normal elderly control subjects (NC). Methods: This study used cross-sectional and longitudinal IADL scale data from MCI and NC subjects followed at an Alzheimer's Disease Center. Results: On a 52-point scale, MCI subjects (n = 30) scored significantly lower than NC subjects (n = 30) on the IADL scale (total score 47.17 vs. 48.77 points; t (58) = 2.34, p = .011) and its Memory subscale (5.27 vs. 6.6 points; t (58) = 3.29, p = .002). Examination of annualized IADL scale change scores revealed that 50% of MCI subjects had declined by one point, compared with 29% of NC. Conclusion: A direct IADL measure for dementia patients is able to detect small differences between MCI and NC and cross-sectionally and longitudinally, but does not distinguish between groups.