Incidence and predictors of excess disability in walking among nursing home residents with middle-stage dementia: a prospective cohort study

Background: Inability to walk compromises the well-being of the growing number of nursing home residents with dementia. The purpose of this study was to estimate the incidence and identify predictors of walking disability that may be remediable. Methods: A cohort was followed fortnightly for a year in15 nursing homes in western Canada. The study participants comprised 120 ambulatory residents with middle-stage Alzheimer's, vascular or mixed dementia. Standardized measures of potential predictors of disability included the Charlson Comorbidity Index, Global Deterioration Scale, and Professional Environment Assessment Protocol. Walking disability was defined as using a wheelchair to go to meals in the dining room. Results: Incidence of walking disability was 40.8% (95% confidence interval (CI): 32.7-50.2). Approximately half of this (27.0%; 95% CI: 19.7-36.5) was excess disability. Residents with more advanced dementia and living in a less supportive nursing home environment experienced an increased hazard of walking disability (Hazard Ratio (HR): 2.1; 95% CI: 1.2-3.8 and HR: 2.4; 95% CI: 1.3-4.4 respectively). After adjusting for age, comorbidity and stage of dementia, predictors of excess disability in walking included using antidepressants (HR: 2.2; 95% CI: 1.02-4.6), and not using cognitive enhancers (HR: 2.6; 95% CI: 1.03-6.4). Conclusions: Over half of walking disability in nursing home residents with middle-stage dementia may be modifiable. Creating supportive environments, ensuring access to cognitive enhancer drugs, and preventing and treating depression and the adverse effects of antidepressants, may help to reduce walking disability and excess disability.