Study settings & sample:~This is an observational, retrospective -case-control, single-center study. This study will include patients who meet the inclusion criteria followed in the Department of Rheumatology and Rehabilitation, Tanta University Hospital, Tanta, Egypt.~Data will be taken from the medical records of patients with rheumatoid arthritis in the outpatient clinic of the Rheumatology and Rehabilitation Department, Tanta University Hospital, Tanta, Egypt. All patients will sign the informed consent form authorizing the collection of these data.~Group classification A) Patients with rheumatoid arthritis using hydroxychloroquine as a part of their treatment regimen.~b) Patients with rheumatoid arthritis not using hydroxychloroquine as a part of their treatment regimen.~Data will be collected and analyzed from patient medical records. It will include the following:~Epidemiologic, demographic, and clinical data.~Severity of rheumatoid arthritis.~Rheumatoid arthritis activity state using the Clinical Disease Activity Index~Dose and duration of hydroxychloroquine~Need for hospitalization, length of hospital stay, and ICU admission including the need for mechanical ventilation.~Duration from the start of symptoms until clinical cure.~Severity of COVID-19 disease according to the World Health Organization interim guidance~Prognosis.~Laboratory investigations and imaging:~Complete blood count.~Renal and liver function tests.~Random blood sugar.~Lactate dehydrogenase, D-dimer.~Serum ferritin, C-reactive protein,~Chest radiographs or CT scan
evaluation of the clinical course of COVID-19 in a cohort of patients with rheumatoid arthritis treated with or without hydroxychloroquine.