Impact of stroke‐associated pneumonia on mortality, length of hospitalization, and functional outcome

Objectives: Stroke‐associated pneumonia (SAP) is common and associated with adverse outcomes. Data on its impact beyond 1 year are scarce.

Materials and methods: This observational study was conducted in a cohort of stroke patients admitted consecutively to a tertiary referral center in the east of England, UK (January 2003‐April 2015). Logistic regression models examined inpatient mortality and length of stay (LOS). Cox regression models examined longer‐term mortality at predefined time periods (0‐90 days, 90 days‐1 year, 1‐3 years, and 3‐10 years) for SAP. Effect of SAP on functional outcome at discharge was assessed using logistic regression.

Results: A total of 9238 patients (mean age [±SD] 77.61 ± 11.88 years) were included. SAP was diagnosed in 1083 (11.7%) patients. The majority of these cases (n = 658; 60.8%) were aspiration pneumonia. After controlling for age, sex, stroke type, Oxfordshire Community Stroke Project (OCSP) classification, prestroke modified Rankin scale, comorbidities, and acute illness markers, mortality estimates remained significant at 3 time periods: inpatient (OR 5.87, 95%CI [4.97‐6.93]), 0‐90 days (2.17 [1.97‐2.40]), and 91‐365 days (HR 1.31 [1.03‐1.67]). SAP was also associated with higher odds of long LOS (OR 1.93 [1.67‐2.22]) and worse functional outcome (OR 7.17 [5.44‐9.45]). In this cohort, SAP did not increase mortality risk beyond 1 year post‐stroke, but it was associated with reduced mortality beyond 3 years.

Conclusions: Stroke‐associated pneumonia is not associated with increased long‐term mortality, but it is linked with increased mortality up to 1 year, prolonged LOS, and poor functional outcome on discharge. Targeted intervention strategies are required to improve outcomes of SAP patients who survive to hospital discharge.