The clinical presentation and progression of COVID-19 in patients is highly variable,
which makes it difficult for clinicians to triage patients and determine their prognostic
risk.

The (Coronavirus Clinical Characterisation Consortoum) 4C mortality score is an
accessible risk stratification score developed by the International Severe Acute
Respiratory and Emerging Infections Consortium (ISARIC) based on eight different
parameters: age, sex, number of comorbidities, respiratory rate, peripheral oxygen
saturation, level of consciousness (Glasgow Coma Scale), urea or blood urea nitrogen
(BUN) level, and C reactive protein (CRP). It was derived and internally validated on a
large, diverse cohort within the United Kingdom but requires external validity to confirm
its generalizability. A recent validation study demonstrated that the score could be
simplified by deleting CRP item which is favorable to its widespread use. The study aim
to validate a modified 4C score.

Methods

This is a multicenter retrospective observational, cohort study of patients admitted to
five Tunisian university hospitals (Fattouma Bourguiba Hospital Monastir, Sahloul
Hospital Sousse, Farhat Hached Hospital Sousse, Taher Sfar Hospital Mahdia, Habib
Bourguiba Hospital Sfax, Traumatology and Burns Center Tunis), the study included medical
records of all adult patients with confirmed COVID-19 infection who were hospitalized
from January 2020 and November 2022. A confirmed case of COVID-19 was defined by a
positive reverse transcriptase-PCR (RT-PCR) assay of a nasopharyngeal swab associated
with compatible clinical manifestations. Incomplete electronic record were excluded from
the analysis.

Anamnesis, clinical, paraclinical, radiological, and outcome data were collected using a
validated electronic case report form (eCRF). The primary outcomes measure was
in-hospital death from any cause.