Severe Dementia and Adverse Outcomes of Nursing Home‐Acquired Pneumonia: Evidence for Mediation by Functional and Pathophysiological Decline

Abstract

OBJECTIVES: To assess whether the severity of dementia is related to unfavorable outcomes of nursing home-acquired pneumonia and how this relationship is mediated. DESIGN: Prospective cohort study. SETTING: Psychogeriatric wards of 61 nursing homes in the Netherlands. MEASUREMENTS: Dementia severity and the possible mediators swallowing disturbance, aspiration, insufficient food intake, weight loss, and dehydration were measured and related to the following outcomes: death (rate), cure rate, and increase in discomfort at the onset of pneumonia. PARTICIPANTS: Demented patients (n = 374) treated with antibiotics for pneumonia. RESULTS: Dementia severity was independently related to death rate within the first week after pneumonia (hazard rate ratio = 3.0 for the most severely demented quartile versus the least demented quartile, 95% confidence interval (CI) = 1.1-8.3) and to 3-month mortality (odds ratio (OR) 2.5, 95% CI = 1.1-5.4). The latter relation was in part mediated by aspiration and weight loss (OR dementia severity adjusted for these mediators declined from 2.5 to 1.9, 95% Cl = 0.8-4.3). Dementia severity was not related to cure rate within 2 weeks nor to an in-crease in discomfort after 3 days compared with before the pneumonia. CONCLUSION: The functional and pathophysiological consequences of progressive dementia account in part for increased 3-month mortality after pneumonia. Mid-term mortality is expected to be high only in the most severely demented patients and in less severely demented patients who aspirated or who lost weight. Implications for end-of-life decision-making and effectiveness of preventive and curative interventions are discussed.