Covid-19 mortality risk factors:  Survival analysis of the hospitalized cohort in Sahloul university hospital in Tunisia [version 1; peer review: awaiting peer review]

Background Tunisia was one of the most affected nations with COVID-19 disease. The clinical features of this illness range from asymptomatic illness to death. Aim To analyse the survival of patients admitted to a Tunisian tertiary care center (Sahloul University Hospital) and identify independent predictive factors for hospital COVID-19 mortality. Methods A longitudinal study was conducted among confirmed COVID-19 patients hospitalized in Sahloul University Hospital between September 2020 and September 2022. Cox univariate regression was used to calculate the Hazard Ratio (HR) of death for patient characteristics regarding the time at risk. Risk factors with a p value of 0.2 or less in the univariate analysis were initially included in the multivariate Cox regression models. Results During the study at Sahloul Hospital, 1978 patients were hospitalized, averaging 55.65 years in age (± 21.39). Among them, 417 deaths occurred, with a median survival of 30 days (± 3.11) [23.904-36.096]. Factors significantly affecting the survival curve were: Age, male gender, comorbidities, diabetes, hypertension, endocrine diseases, obesity, intubation, and ICU admission Multilevel survival analyses revealed that hypertension (aHR 1.24; CI [1.02-1.52]; p=0.028), ICU admission (aHR 12.20- CI [9.56-15.57]; p