Psychosocial and Physical Functioning Predictors of Everyday Functioning in The Kaiser Healthy Aging and Diverse Life Experience (KHANDLE) Study

Abstract

AbstractBackgroundWhile Alzheimer’s disease and associated cognitive impairments are major contributors to functional decline, other variables including physical functioning and psychosocial variables may also impact functional status. Our study examined how psychosocial factors (depression, loneliness, and emotional support) and physical functioning (gait speed and grip strength) may independently contribute to instrumental activities of daily living (IADL) functioning among a diverse ethnoracial cohort.MethodThe Kaiser Healthy Aging and Diverse Life Experience (KHANDLE) study is a diverse cohort of long‐term members of an integrated healthcare delivery system ages ≥65, without a dementia diagnosis at time of recruitment. At enrollment, participants completed self‐report IADL measure, neuropsychological testing, physical functioning assessment (grip strength and walk speed), and self‐report psychosocial inventories assessing depression, loneliness, and perceived emotional support through the NIH Toolbox. Analytic sample included 1,243 participants (395 Caucasian (32%), 331 African American (27%), 292 Asian (23%), and 225 Latino (18%)). Cumulative logit models adjusting for cognition and demographics were used to determine significant predictors of IADL functioning, both in separate and combined models. Possible effect modification by race/ethnicity were assessed through interaction terms.ResultAverage baseline age was 75.5 and 59% were female. In separate models, gait speed, grip strength, loneliness, and emotional support were significant predictors of IADL functioning after controlling for cognition and demographics. Depression was not a significant predictor. When adding all significant variables into a single model as independent predictors, slower gait and greater loneliness were associated with more IADL difficulty, while stronger grip strength and more emotional support was associated with less IADL difficulty. Emotional support was no longer a significant predictor of IADL functioning. Interaction terms between independent variables and race were not significant.ConclusionVery few studies have simultaneously examined psychosocial factors and physical functioning as predictors of everyday functioning, particularly among a diverse ethnoracial sample. Our results indicate that independent of cognition, slower gait and greater loneliness were independently associated with worse IADL functioning, while stronger grip strength was associated with better IADL functioning. Such findings have important implications for identifying older adults at risk for disability and for treatments that could prevent excess disability.