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

Acta Neurol Scand. 2018 Oct;138(4):293-300. doi: 10.1111/ane.12956. Epub 2018 May 10.

Abstract

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.

Keywords: acute stroke; mortality; prognosis; stroke-associated pneumonia.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Cohort Studies
  • Comorbidity
  • Female
  • Follow-Up Studies
  • Hospitalization / trends
  • Humans
  • Length of Stay / trends*
  • Male
  • Middle Aged
  • Patient Discharge / trends
  • Pneumonia / diagnosis*
  • Pneumonia / etiology
  • Pneumonia / mortality*
  • Prognosis
  • Recovery of Function*
  • Stroke / complications
  • Stroke / diagnosis*
  • Stroke / mortality*
  • Treatment Outcome