Mild Behavioral Impairment and Quality of Life in Community Dwelling Older Adults.

Objectives: Mild behavioral impairment (MBI) is a dementia risk indicator in older adults characterized by later-life emergent and persistent neuropsychiatric symptoms. Quality of life (QoL) is a multi-dimensional concept encompassing physical, spiritual, and emotional well-being. QoL aims to measure and quantify perceptions of individual health, well-being, standard of living, personal fulfillment, and satisfaction. As MBI symptoms may arise from early-stage neurodegenerative disease, MBI may contribute to declining QoL before dementia onset. In this study, we investigated the relationship between symptoms of MBI and QoL in older adults.

Methods: The sample comprised 1107 individuals aged ≥ 50 years from the Canadian Platform for Research Online to Investigate Health, Quality of Life, Cognition, Behavior, Function, and Caregiving in Aging (CAN-PROTECT). Multivariable linear regressions were used to model the associations between MBI symptom severity (exposure), measured using the MBI Checklist (MBI-C), and QoL (outcome) assessed by the EuroQol-5D (EQ-5D, higher score = poorer QoL) and the novel Quality of Life and Function Five Domain Scale (QFS-5) (QFS-5, lower score = poorer QoL). Covariates were age, sex, cognition, education, ethnocultural origin, marital status, employment status, high blood pressure, heart disease, and diabetes. Moderation analysis explored potential sex differences. A sensitivity analysis was performed removing anxiety/depression items from the EQ-5D score.

Results: Across the sample (mean age = 64.4 ± 7.2, 79.4% female) every 1-point increase in MBI-C score was associated with a 0.06-point standard deviation (SD) increase in EQ-5D score (95% confidence interval (CI): 0.05-0.06, p < 0.001) and 0.08 SD decrease in QFS-5 score (95% CI: -0.09 to -0.08, p < 0.001). Neither association depended on sex (p = 0.59 and p = 0.41, respectively). The association remained significant after removing anxiety/depression items from the EQ-5D score (β = 0.04, 95% CI: 0.03- 0.04, p < 0.001).

Conclusions: The study shows that MBI is associated with poorer QoL, independent of sex, on two QoL scales. We addressed depression/anxiety items in the EQ-5D as a potential confounder for the observed MBI-QoL association by conducting a sensitivity analysis that excluded those items from the EQ-5D total score and by employing a novel measure of QoL (QFS-5) that excludes psychiatric symptoms from measurement of QoL. Associations of MBI with the novel QFS-5 were similar to associations between MBI and the EQ-5D. Finding interventions to reduce the burden of MBI symptoms might improve quality of life.