Do Stroke Care Processes Modify Clinical Outcomes in Patients with Stroke-Associated Pneumonia? A Registry Cohort Study in England and Wales

Introduction: It is not known whether modern stroke unit care reduces the impact of stroke complications, such as stroke-associated pneumonia (SAP), on clinical outcomes. We investigated the relationship between SAP and clinical outcomes, adjusting for the confounding effects of stroke care processes and their timing. Methods: The Sentinel Stroke National Audit Programme provided patient data for all confirmed strokes between April 2013 and December 2018. SAP was defined as new antibiotic initiation for suspected pneumonia within the first 7 days from stroke admission. We compared outcomes after SAP versus non-SAP in appropriate multilevel mixed models. Each model was adjusted for patient and clinical characteristics, as well as markers of stroke care and their timing within the first 72 h. The appropriate effect estimates and corresponding 95% confidence intervals (CIs) were reported. Results: Of 201,778 patients, SAP was present in 14.2%. After adjustment for timing of acute stroke care processes and clinical characteristics, adverse outcomes remained for SAP versus non-SAP patients. In these adjusted analyses, patients with SAP maintained an increased risk of longer length of in-hospital stay (IRR of 1.27; 95% CI: 1.25, 1.30), increased odds of worse functional outcome at discharge (OR of 2.9; 95% CI: 2.9, 3.0), and increased risk of in-hospital mortality (HR of 1.78; 95% CI: 1.74, 1.82). Conclusion: We show for the first time that SAP remains associated with worse clinical outcomes, even after adjusting for processes of acute stroke care and their timing. These findings highlight the importance of continued research efforts aimed at preventing SAP.