On May 11, 2020, a study was published in JAMA Network that attempts to answer the question whether there is an association between use of hydroxychloroquine, with or without azithromycin, and in-hospital mortality among patients with coronavirus disease 2019 (COVID-19).

In a retrospective cohort study of 1,438 patients hospitalized in metropolitan New York, compared with treatment with neither drug, the adjusted hazard ratio for in-hospital mortality for treatment with hydroxychloroquine alone was 1.08, for azithromycin alone was 0.56, and for combined hydroxychloroquine and azithromycin was 1.35. None of these hazard ratios were statistically significant.

The results showed that among patients hospitalized with COVID-19, treatment with hydroxychloroquine, azithromycin, or both was not associated with significantly lower in-hospital mortality.