Introduction: The second iteration of the National Early Warning Score (NEWS2) has been widely adopted for predicting patient deterioration in healthcare settings using routinely collected physiological observations. The use of NEWS2 has been shown to reduce in-hospital mortality, but it has limited accuracy in the prediction of clinically important outcomes, especially over longer time periods. The increasing implementation of digital patient observations and health records presents an opportunity to investigate whether the addition of individual patient characteristics and information about their care-setting, would improve the predictive accuracy of the score. Methods and analysis: This protocol describes the work to determine whether the performance of the current NEWS2 system could be improved by the use of additional variables. The project has been designed after an extensive scoping review of existing literature on NEWS2 and an exploration of retrospective cohort data in The Newcastle upon Tyne Hospitals NHS Foundation Trust, with input from key clinical stakeholders. Ethics and dissemination: The project has received competitive funding following peer-review, from the NIHR Newcastle Biomedical Research Centre as an Interdisciplinary Research Award. Ethical approval has been requested. Findings are expected to be produced by June 2025, and will be disseminated at symposia, conferences and in journal publications.

The authors have declared no competing interest.

This work was supported by the National Institute for Health and Care Research (NIHR) Newcastle Biomedical Research Centre (BRC) based at the Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle University, and the Cumbria, Northumberland, and Tyne and Wear (CNTW) NHS Foundation Trust. The views expressed in this publication are those of the authors and not necessarily those of the NIHR BRC, or any of the authors affiliated universities. The Newcastle BRC paid the open-access publication fee. The funding body was not involved in the study design, data collection or analysis, or the writing and decision to submit the article for publication.

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

Yes

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

Newcastle Hospitals NHS Foundation Trust gave ethical approval for this work.

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I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

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I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

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