Life expectancy for community-dwelling persons with dementia and severe disability

Understanding life expectancy can help persons with dementia, their care partners, and policymakers plan for what lies ahead. We sought to determine life expectancy and predictors of mortality for community-dwelling persons with dementia and severe disability.

Using the National Health and Aging Trends Study (NHATS) linked to Medicare claims, we identified community-dwelling respondents age 65+ who entered NHATS in 2011 with dementia and severe disability (defined as three impairments in activities of daily living), or who subsequently met criteria for dementia and then severe disability. We estimated time to death based on the timing of meeting severe disability criteria. We conducted parametric survival analyses using a Gompertz distribution to calculate risk of death and predicted median time to death. Predictors included demographic, functional, clinical characteristics, and behavioral symptoms (assessed among NHATS respondents with proxy interviews).

Among 842 community-dwelling persons with dementia and severe disability, 80.5% died during the study period. After adjusting for age and gender, overall predicted median time to death was 1.7 years (25th percentile 0.6, 75th percentile 3.8 years). Six notable characteristics were associated with shorter life expectancy: 1) older age (90+), with a predicted median time to death of 1.0 year (0.4, 2.1); 2) being bedbound, 1.1 years (0.4, 2.3); 3) being homebound, 1.2 years (0.5, 2.6); 4) having comorbid cancer, 1.2 years (0.5, 2.6); 5) unintended weight loss, 1.4 years (0.5, 3.1); and 6) comorbid depression, 1.5 years (0.6, 3.3).

Community-dwelling persons with dementia and severe disability lived a median of 1.7 years. Clinicians can use the study findings to provide anticipatory guidance to patients and care partners, and policymakers to inform design of longitudinal supportive services.