Objective: To analyze the risk of systemic lupus erythematosus (SLE) flare after admission for COVID-19.
Methods: We performed a matched cohort study using the Assistance Publique-Hôpitaux de Paris Clinical Data Warehouse which collects structured medical, biological and administrative information from 11 million patients in Paris area, France. Each SLE patient hospitalized with a COVID-19 diagnosis code between March 2020 and December 2021 was matched to one SLE control patient with an exact matching procedure using age ±3 years, gender, chronic kidney disease, end-stage renal disease, and serological activity.