Objective: : A key component of successful aging is the ability to independently perform instrumental activities of daily living (IADL). We examined the ability to perform multiple IADL tasks in relation to mild cognitive impairment (MCI) defined on purely neuropsychological grounds.
Design: : Cross-sectional study.
Setting: : Population-based cohort in southwestern Pennsylvania.
Participants: : One thousand seven hundred thirty-seven community-dwelling adults age 65 years and older.
Measurements: : Classification of MCI based on performance with reference to norms in the cognitive domains of memory, language, attention, executive, and visuospatial functions. The ability to perform seven IADL tasks (traveling, shopping, preparing meals, doing housework, taking medications, handling personal finances, and using the telephone) as assessed by the Older Americans Resources and Services scale.
Results: : Those with cognitively defined MCI were more likely to be dependent in at least one IADL task, as well as in each individual IADL task, than cognitively normal participants. Better memory and executive functioning were associated with lower odds of IADL dependence in MCI. Across the subtypes of MCI, those with the multiple-domain amnestic subtype were most likely to be dependent in all IADL tasks, with better executive functioning associated with lower risk of dependence in select IADL tasks in this group.
Conclusions: : Mild impairment in cognition is associated with difficulty performing IADL tasks at the population level. Understanding these associations may help improve prediction of the outcomes of MCI. It may also allow appropriate targeting of cognitive interventions in MCI to potentially help preserve functional independence.