Declaration provenance — 8 October 2026

The final author contribution statement, rule-level clinical-code review, authorised database access, absence of patient/public involvement, absence of additional acknowledgements, all-author approval and absence of overlapping manuscripts/preprints were confirmed by the submitting author during finalisation. No additional local institutional approval requirement was reported by the author. No local review-board decision document, waiver letter or certificate number was supplied or independently verified, and no such number or local committee decision is asserted in the manuscript.

Original-resource governance was checked independently:
1. MIMIC-IV 3.1, Ethics and Access sections. The BIDMC Institutional Review Board reviewed patient-information collection/resource creation, waived informed consent and approved data sharing. Access requires credentialing, training and a signed data-use agreement.
https://physionet.org/content/mimiciv/3.1/
2. Pollard et al. The eICU Collaborative Research Database, a freely available multi-center database for critical care research. Scientific Data. 2018;5:180178. Deidentification follows HIPAA safe-harbour standards; users follow credentialed access requirements.
https://doi.org/10.1038/sdata.2018.178
3. Same-database wording precedent only: Ding et al. Temporal dimensions of oxygen saturation exposure and clinical outcomes in critically ill patients: a retrospective multi-database cohort study. Critical Care. 2025;29:402.
https://doi.org/10.1186/s13054-025-05652-9

The third reference supports a publication-wording precedent; it does not establish the present authors' local institutional arrangements. Other papers' approval/certification identifiers were not copied. The present manuscript uses its existing original-database citations [8–11]. Authors should retain their actual access records and the basis for their secondary-use ethics statement in case documentation is requested.
