Development and external validation of a prediction model for the transition from mild to moderate or severe form of COVID-19.

"Declarations GuarantorThe scientific guarantor of this publication is Pr Francois Laurent. Conflict of interestM. Zysman receives payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing, or educational events from CSL Behring, GSK, Boeringer Ingelheim, and AstraZeneca. M. Zysman receives support for attending meetings and/or travel from Chiesi and AstraZeneca. The remaining authors of this manuscript declare no relationships with any companies, whose products or services may be related to the subject matter of the article. Statistics and biometryJulien Asselineau, Eric Frison, and Rodolphe Thiebaut kindly provided statistical advice for this manuscript. Informed consentWritten informed consent was waived by the Institutional Review Board. Ethical approvalInstitutional Review Board approval was obtained. Study subjects or cohorts overlapNo study subjects or cohorts have been previously reported. Methodologyretrospectivediagnosticmulticenter study Conflict of interest M. Zysman receives payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing, or educational events from CSL Behring, GSK, Boeringer Ingelheim, and AstraZeneca. M. Zysman receives support for attending meetings and/or travel from Chiesi and AstraZeneca. The remaining authors of this manuscript declare no relationships with any companies, whose products or services may be related to the subject matter of the article."

"Funding This study has received funding by the Interregional Hospital Program of Clinical Research (“Programme Hospitalier de Recherche Clinique Interregional” 2020, PHRCI 2020_20-016). The funder played no in the study or the preparation of the manuscript."

"Clinical Trial Registration NCT04481620."