Introduction Early identification of a patient with infection who may develop sepsis is of utmost importance. Unfortunately, this remains elusive because no single clinical measure or test can reflect complex pathophysiological changes in patients with sepsis. However, multiple clinical and laboratory parameters indicate impending sepsis and organ dysfunction. Screening tools using these parameters can help identify the condition, such as SIRS, quick SOFA (qSOFA), National Early Warning Score (NEWS), or Modified Early Warning Score (MEWS). We aim to externally validate qSOFA, SIRS, and NEWS/NEWS2/MEWS for in-hospital mortality among adult patients with suspected infection who presenting to the emergency department. Methods and analysis PASSEM study is an international prospective external validation cohort study. For 9 months, each participating centre will recruit consecutive adult patients who visited the emergency departments with suspected infection and are planned for hospitalisation. We will collect patients' demographics, vital signs measured in the triage, initial white blood cell count, and variables required to calculate Charlson Comorbidities Index; and follow patients for 90 days since their inclusion in the study. The primary outcome will be 30-days in-hospital mortality. The secondary outcome will be intensive care unit (ICU) admission, prolonged stay in the ICU (i.e., >72 hours), and 30- as well as 90-days all-cause mortality. The study started in December 2021 and planned to enrol 2851 patients to reach 200 in-hospital death. The sample size is adaptive and will be adjusted based on prespecified consecutive interim analyses. Ethics and dissemination The Aseer Regional Committee for Research Ethics in the General Directorate of Health Affairs-Aseer Region has approved this study. Informed consent is not required for this study due to its complete observational nature and absence of interventions or invasive procedures. We will publish study's results in peer-reviewed journals and may present them at scientific conferences.

The authors have declared no competing interest.

This study did not receive any funding

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The Aseer Regional Committee for Research Ethics in the General Directorate of Health Affairs Aseer Region has approved this study

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All data produced in the present study are available upon reasonable request to the authors