Definitions of hospital-acquired pneumonia in trauma research: a systematic review

Purpose: What are reported definitions of HAP in trauma patient research? Methods: A systematic review was performed using the PubMed/MEDLINE database. We included all English, Dutch, and German original research papers in adult trauma patients reporting diagnostic criteria for hospital-acquired pneumonia diagnosis. The risk of bias was assessed using the MINORS criteria. Results: Forty-six out of 5749 non-duplicate studies were included. Forty-seven unique criteria were reported and divided into five categories: clinical, laboratory, microbiological, radiologic, and miscellaneous. Eighteen studies used 33 unique guideline criteria; 28 studies used 36 unique non-guideline criteria. Conclusion: Clinical criteria for diagnosing HAP—both guideline and non-guideline—are widespread with no clear consensus, leading to restrictions in adequately comparing the available literature on HAP in trauma patients. Studies should at least report how a diagnosis was made, but preferably, they would use pre-defined guideline criteria for pneumonia diagnosis in a research setting. Ideally, one internationally accepted set of criteria is used to diagnose hospital-acquired pneumonia. Level of evidence: Level III.