Predictors of mortality and disability in stroke-associated pneumonia

Abstract

Whilst stroke-associated pneumonia (SAP) is common and associated with poor outcomes, less is known about the determinants of these adverse clinical outcomes in SAP. To identify the factors that influence mortality and morbidity in SAP. Data for patients with SAP (n = 854) were extracted from a regional Hospital Stroke Register in Norfolk, UK (2003–2015). SAP was defined as pneumonia occurring within 7 days of admission by the treating clinicians. Mutlivariable regression models were constructed to assess factors influencing survival and the level of disability at discharge using modified Rankin Scale [mRS]. Mean (SD) age was 83.0 (8.7) years and ischaemic stroke occurred in 727 (85.0%). Mortality was 19.0% at 30 days and 44.0% at 6 months. Stroke severity assessment using National Institutes of Health Stroke Scale was not recorded in the data set although Oxfordshire Community Stroke Project was Classification. In the multivariable analyses, 30-day mortality was independently associated with age (OR 1.04, 95% CI 1.01–1.07, p = 0.01), haemorrhagic stroke (2.27, 1.07–4.78, p = 0.03) and pre-stroke disability (mRS 4–5 v 0–1: 6.45, 3.12–13.35, p < 0.001). 6-month mortality was independently associated with age (< 0.001), pre-stroke disability (p < 0.001) and certain comorbidities, including the following: dementia (6.53, 4.73–9.03, p < 0.001), lung cancer (2.07, 1.14–3.77, p = 0.017) and previous transient ischemic attack (1.94, 1.12–3.36, p = 0.019). Disability defined by mRS at discharge was independently associated with age (1.10, 1.05–1.16, p < 0.001) and plasma C-reactive protein (1.02, 1.01–1.03, p = 0.012). We have identified non-modifiable determinants of poor prognosis in patients with SAP. Further studies are required to identify modifiable factors which may guide areas for intervention to improve the prognosis in SAP in these patients.