Core outcome set for trials evaluating the management of community-acquired and nosocomial pneumonia in adults: an ERS statement

Background: Clinical trials assessing the management of pneumonia use heterogeneous outcomes, often lacking patient relevance or standardisation. We developed two core outcome sets (COSs) for future clinical trials evaluating interventions in community-acquired pneumonia (CAP) and nosocomial pneumonia (hospital-acquired pneumonia and ventilator-associated pneumonia) to improve the consistency and comparability of evidence. Methods: A multistage, multistakeholder process was undertaken, comprising 1) a systematic review of previously used outcomes conducted by our team, 2) qualitative interviews with patients and 3) a two-round online Delphi survey involving 289 participants (patients, relatives and healthcare professionals) from 58 countries. This diverse sample ensured a broad representation of clinical and patient perspectives. Final outcomes were agreed upon through structured voting in two virtual consensus meetings in April 2025. Results: The final COS for CAP includes: treatment success/failure, all-cause mortality, serious adverse events, readmissions (admission for community-based trials), duration of symptoms and time to clinical stability (for hospitalised patients). The nosocomial pneumonia COS includes: treatment success/failure, all-cause mortality, serious adverse events, readmission and need for ventilatory support. The panel suggested measuring mortality at 30 days from study enrolment and readmission at 30 days post-discharge. Conclusions: These COSs, developed by a European Respiratory Society Task Force, provide a standardised framework for outcome selection in pneumonia trials and were informed by broad stakeholder input, including patients. Their use is expected to improve the relevance, quality and comparability of future research in pneumonia.