Functional Competence and Cognition in Individuals With Amnestic Mild Cognitive Impairment.

OBJECTIVE The objective of this study is to characterize functional competence (measure of assistance needed for independence) on Performance Assessment of Self-Care Skills (PASS) Cognitively Mediated Instrumental Activities of Daily Living (C-IADL), in individuals with amnestic mild cognitive impairment (aMCI). It aims to determine: (1) the association of functional competence on PASS C-IADL tasks with neurocognitive test performance in aMCI, (2) its ability to discriminate individuals with aMCI from healthy control (HC) individuals, and (3) its added value in discriminating aMCI from HC individuals when combined with neurocognitive test performance. DESIGN Cross-sectional secondary analysis of baseline data from a cohort of individuals enrolled in a clinical trial (NCT02386670). SETTING Five university-affiliated outpatient clinics in Toronto, Canada. PARTICIPANTS aMCI (N = 137) and HC (N = 51) participants, all aged 60 years or older. METHODS We assessed the relationship between functional competence on three C-IADL PASS tasks (shopping, bill paying, and checkbook balancing) and neurocognitive tests in 137 participants with aMCI using multiple linear regressions. Additionally, we constructed receiver operating characteristic curves to assess the role of PASS functional competence in discriminating between 137 aMCI and 51 HC participants. RESULTS Functional competence on PASS was significantly associated with tests of verbal memory, information processing speed, and executive function. It demonstrated 79% accuracy in discriminating aMCI from HC participants. Combining functional competence on PASS with individual neurocognitive tests significantly increased the discriminant accuracy of individual tests, and neurocognitive test scores combined with functional competence on PASS had the highest discriminant accuracy (94%). CONCLUSION Functional competence on PASS is predicted by the underlying cognitive deficits and possibly captures additional element of effort that could improve the diagnostic accuracy of aMCI when combined with neurocognitive tests. Thus, PASS appears to be a promising tool for assessment of functional competence in aMCI in clinical or research settings.