Conclusions
Despite equipoise regarding the benefit of hydroxychloroquine/azithromycin treatment for COVID-19 infection, these medications continue to be used in large clinical trials both in the US and across the world. This study demonstrates that the risk of QTc prolongation by these medications is enhanced in the setting of renal failure, older age, baseline QTc prolongation and the concomitant use of other QT-prolonging medications in patients with severe COVID-19 infection. A better understanding of these factors associated with QTc prolongation is important for safe administration of these medications, especially in light of data showing low efficacy in COVID-19 treatment.