Contributions of environment, comorbidity, and stage of dementia to the onset of walking and eating disability in long-term care residents

Abstract

Objectives: To estimate the relative effects of environment, comorbidities, stage of dementia and other variables on disability onset.

Design: A 1-year prospective cohort study was conducted in which the walking and eating abilities of long-term care residents were observed fortnightly. Structural equation modeling was used to assess the contributions of individual and environmental factors to the onset of disability.

Setting: Fifteen nursing homes in western Canada.

Participants: One hundred twenty residents with middle-stage Alzheimer disease or related dementia.

Measurements: Environmental quality was assessed using the Professional Environmental Assessment Protocol, comorbidity using the Charlson Comorbidity Index, and stage of dementia using the Global Deterioration Scale.

Results: More-advanced baseline dementia had a direct effect on onset of walking and eating disability (standardized maximum likelihood estimate (SMLE) = 0.24, P = .006). Resident environment (SMLE = -0.25, P = .007) and comorbidities (SMLE = 0.32, P < .001) influenced disability onset approximately as strongly as stage of dementia. Smaller and publicly owned facilities provided superior environmental quality, which indirectly contributed to a delay in onset of walking and eating disability.

Conclusion: Environmental quality and extent of comorbidity are at least as important as progression of dementia in initiating or delaying the onset of disability.