Self-Efficacy Mediates the Association Between Physical Function and Perceived Quality of Life in Individuals with Mild Cognitive Impairment.

BACKGROUND: Research has shown that individuals with mild cognitive impairment (MCI) value quality of life (QoL) above and beyond cognitive function or other potential outcomes in MCI. There is evidence supporting the negative impact of poor physical function on QoL ratings. OBJECTIVE: The study explored whether a modified measure of self-efficacy for managing MCI and education mediated and/or moderated the relationship between physical function and QoL in persons with MCI. METHODS: Baseline data from 200 participants with MCI were obtained from a larger study assessing the effectiveness of a behavioral intervention. Physical function was assessed by the Short Physical Performance Battery. QoL was assessed with the Quality of Life in Alzheimer's Disease scale. Memory-related self-efficacy was assessed using a modified 9-item version of the Chronic Disease Self-Efficacy Scales. Mediation and moderation analyses tested the hypotheses that self-efficacy and education alter the association between physical function and QoL in individuals with MCI. All analyses were adjusted for age, cognitive severity, and sex. RESULTS: Self-efficacy for managing MCI was a significant mediator of the association between physical function and perceived QoL. Individuals with better physical function reported higher self-efficacy which was associated with higher QoL ratings. CONCLUSIONS: Greater self-efficacy for managing MCI mediated the negative association between physical function and quality of life in this exploratory study. Interventions aimed at enhancing memory self-efficacy in MCI may improve perceived QoL, even in the presence of poor physical function. Future research is needed to investigate this further.