Dementia, lower respiratory tract infection, and long-term mortality

To examine long-term mortality and its determinants in nursing home residents with dementia diagnosed with a lower respiratory tract infection (LRI).

US (Missouri) nursing home residents (541) and Dutch residents (403) with dementia who were treated with antibiotics for an LRI.

Prospective studies of nursing home-acquired LRI in the US (Missouri) and in the Netherlands. Measurements included demographics, indicators of acute illness, general health condition, intake problems, and comorbid disease. Six-month mortality rates were calculated and Cox proportional hazards models were developed for mortality up to 2 years after diagnosis.

Six-month mortality was 48.8% among Dutch residents and 36.4% among US residents. After multivariable adjustment, Dutch nationality was not associated with higher long-term mortality. Variables most strongly associated with long-term mortality were activity of daily living dependency and male gender. Other variables associated with outcome were diverse: respiratory difficulty, age, dehydration, congestive heart failure, decreased alertness, decubitus ulcers, Parkinson disease, weight loss/poor nutrition, and pulse rate.

LRI is followed by substantial mortality in the months after diagnosis, indicating high frailty of nursing home residents with dementia who develop LRI. A variety of patient characteristics, including many not directly related to LRI, were consistently associated with long-term mortality in two cohorts with differing illness severity. The results are relevant for informing families, evaluating poor long-term survival in the context of care and treatment, and balancing the potential burdens and benefits of care.