Mahévas (2020)
Clinical Efficacy of Hydroxychloroquine in Patients With covid-19 Pneumonia Who Require Oxygen: Observational Comparative Study Using Routine Care Data
Treatment for COVID-19 (Treated with hydroxychloroquine vs. Not received)
COVID-19 (survival)
Hazard ratio: 0.800 (0.400-1.500) Adjusted model


Prospective observational study

Medical records


181 patients aged 18-80 years with documented severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia who required oxygen but not intensive care. Physicians screened the electronic health records of all patients with COVID-19 pneumonia admitted to four French tertiary hospitals between 12 March and 31 March 2020.

Among the 181 patients eligible for analysis, 84 received hydroxychloroquine within 48 hours of admission, eight received hydroxychloroquine more than 48 hours after admission, and 89 did not receive hydroxychloroquine. The median age of patients was 60 years (interquartile range 52-68 years), and 72% were men. Patients in the treatment group had fewer comorbidities, except for liver cirrhosis. The median interval between symptom onset and admission to hospital was 7 days (interquartile range 5-10 days). Overall, initial severity was well balanced between the groups, except for confusion on admission (0 in the treatment group v 6 (7%) in the control group). Azithromycin was administered to 18% of the participants in the treatment group versus 29% in the control group; amoxicillin and clavulanic acid was given to 52% versus 28%, respectively (excluding cointerventions in patients transferred to the intensive care unit.


33 Day

COVID-19 (survival)


Survival without transfer to intensive care unit


Treatment for COVID-19

hydroxychloroquine at a dose of 600 mg/day (treatment group) and no hydroxychloroquine treatment (control group)

Not received

Treated with hydroxychloroquine

Hazard ratio

0.800 (0.400-1.500)




propensity score: variables in model included age, sex, and comorbidities

No patients received antiviral or anti-inflammatory treatments, including steroids or non-steroidal anti-inflammatory drugs (non-steroidal anti-inflammatory drugs are not used as antipyretics in adults in France and are considered to be contraindicated for COVID-19) before transfer to the intensive care unit.