DOXY-COVID study is a national, observational, retrospective cohort study to compare the risk of severe COVID-19 in doxycycline-treated patients versus non-doxycycline-treated control patients (so-called case-cohort study).
The patient inclusion period corresponds to the main waves associated with the COVID-19 epidemic in France, i.e. from January 1, 2020 to November 30, 2021. Indeed, the time of data access, expected during 2022, would not allow reasonable follow-up of doxycycline-exposed patients from December 1, 2021.
Data of interest collected on these patients are requested over the period from January 1, 2016, through December 31, 2021:
* From January 1, 2016, in order to be able to define a pre-exposure phenotype over a follow-up period of at least 4 years in the French Health Insurance databases (period 2016-2019 inclusive)
* Until December 31, 2021, in order to have at least one month's hindsight on the risk of occurrence of severe forms of COVID-19
