Background: From the beginning of the COVID-19 pandemic, age (most importantly), male gender and various comorbidities were found to be associated with severe forms of COVID-19. There was little information provided for an entire country such as France.

Objectives: To determine medical and socioeconomic risk factors associated with risks of COVID-19-related hospitalization and in-hospital mortality in the entire French country.

Methods: In France, the SNDS healthcare database was used to estimate the risk associated with about fifty diseases or health conditions, for hospitalization primarily related to COVID-19 and COVID-19-related deaths among all people alive on February 15. Cox proportional hazards models were used to estimate hazard ratios (HR) after adjustment for age and gender, and then in models including all variables (adjusted hazard ratios [aHR]).

Results: In a population of 66,050,090 people, 87,809 people (134 per 100,000) were hospitalized for COVID-19 between February 15, 2020 and June 15, 2020 and a subgroup of 15,661 people (24 per 100,000) died in hospital. A much higher risk was observed with increasing age. Men were at higher risk compared to women. Almost all chronic health conditions were positively associated with an increased risk of COVID-19-related hospitalization and in-hospital mortality, with the exception of dyslipidaemia, which was negatively associated. The strongest associations for both COVID-19-related hospitalization and in-hospital mortality were observed in people with Down syndrome (aHR, 7.0 [6.1-8.1] and 22.9 [17.1-30.7], respectively), mental retardation (3.8 [3.5-4.2] and 7.3 [6.1-8.8]), kidney transplantation (4.6 [4.2-5.0] and 7.1 [6.0-8.4]), lung transplantation (3.5 [2.4-5.3] and 6.2 [2.8-14.0]) end-stage renal disease on dialysis (4.2 [3.9-4.4] and 4.7 [4.2-5.2]) and active lung cancer (2.6 [2.4-2.8] and 4.0 [3.5-4.6]). Stratified analyses showed stronger associations in patients under the age of 80 years between the risks for severe forms of COVID-19 and certain chronic diseases such as diabetes or cancer. Strong associations between social deprivation index and risk of COVID-19 were observed in people under the age of 80 years with a twofold higher risk of death among the most deprived compared to the least deprived.

Conclusions: This national cohort study confirms the associations with most diseases and health conditions in France and provides data on less frequent health conditions, which could be useful particularly to target priority populations during present and future vaccination campaigns.