Moderated Poster Australian and New Zealand Stroke Organisation Conference 2025

Characterising incident pneumonia after ischaemic stroke and associated risk factors: A population-based study using linked data (123205)

Lachlan Dalli 1 , Shu Wen Wen 2 , Muideen T. Olaiya 1 , Monique F. Kilkenny 1 3 , Catherine Burns 1 , Connie H.Y. Wong 2 , Ben Rogers 4 , Jenni Ilomaki 5 6
  1. Stroke and Ageing Research, Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Clayton, Victoria, Australia
  2. Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical Centre, Monash University , Clayton, Victoria, Australia
  3. Stroke Theme, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Heidelberg, Victoria, Australia
  4. Monash Infectious Diseases, Monash Health, Clayton, Victoria, Australia
  5. Centre for Medicine Use and Safety, Faculty of Pharmacy and Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
  6. School of Public Health and Preventive Medicine, Monash University, Clayton, Victoria, Australia

Introduction: Survivors of stroke are at a high risk of infection (e.g., pneumonia) which can complicate recovery and worsen prognosis. We aimed to characterise the epidemiology of incident pneumonia after ischaemic stroke.

Methods: A population-wide observational study was undertaken using linked data on all adults (aged ≥35 years) admitted with ischaemic stroke in Victoria between July 2012 and June 2017. The cohort was limited to patients with no previous history of pneumonia who survived to hospital discharge. Incident pneumonia events within 1 year post-stroke were ascertained using hospital admissions and mortality databases. Fine-Gray regression models were used to examine factors associated with incident post-stroke pneumonia, accounting for death as the competing risk.

Results: Among 21,561 patients (45% female; 51% aged ≥75 years), 3,028 (14%) had an incident pneumonia event over the 1-year follow-up period (median 8 days post-stroke [interquartile range: 0–122]). The most common diagnosis was ‘unspecified pneumonia’ (40%) followed by ‘aspiration pneumonia’ (36%). Factors associated with an increased risk of incident pneumonia included: age ≥75 years (vs 35-74 years; sub-distribution hazard ratio [SHR]: 2.59 [95% CI: 2.41–2.77]), increasing Charlson Comorbidity Scores (SHR: 1.18 [95% CI: 1.17–1.20] per 1-point increase), and prior use of corticosteroids (SHR: 1.29 [95% CI: 1.17–1.41]) or antibiotics (SHR: 1.37 [95% CI: 1.27–1.48]) in the 90 days before stroke.

Conclusions: Pneumonia is a common complication following stroke. Patients with a recent history of conditions requiring antibiotic and corticosteroid therapy may be more susceptible to incident post-stroke pneumonia.