Predicting Functional Dependence in Mild Cognitive Impairment: Differential Contributions of Memory and Executive Functions.

BACKGROUND AND OBJECTIVES: Diagnostic criteria for mild cognitive impairment (MCI) exclude functional deficits, yet recent studies suggest that older adults with MCI can exhibit impairment in instrumental activities of daily living (IADL). To assist health care providers in detecting functional vulnerabilities that often precipitate loss of independence, we: (a) compared IADL dependence in MCI to older adults without cognitive impairment and those with dementia, (b) estimated the odds of dependence on specific IADLs in MCI, and (c) investigated the differential contributions of memory and executive functions to IADL dependence. RESEARCH DESIGN AND METHODS: Participants were older adults (Mage = 77.58 ± 11.05) in Maryland, USA (N = 512) community and postacute rehabilitation settings. Analysis was performed on Brief Cognitive Assessment Tool (BCAT) and the Functional Activities Questionnaire (FAQ) data that assessed participants' cognitive functioning and IADL dependence, respectively.
RESULTS: 61.04% of participants with MCI were dependent on one or more IADLs. MCI was associated with significantly greater odds of dependence than normal cognition on 7 of the 10 IADLs (odds ratios = 2.62-4.66). Impairment in memory and executive functions significantly predicted IADL dependence (18.52% of variance beyond demographics); executive functions were the stronger predictor, particularly for complex finances, complex cooking, and remembering events. DISCUSSION AND IMPLICATIONS: IADL dependence can occur even in MCI. Testing suggestive of MCI should alert clinicians to further investigate the older adult's profile of cognitive and functional limitations to highlight targets for caregiver support and promote independence by "right-sizing" community or facility resources.