Hydroxychloroquine with or without Azithromycin in Mild-to-Moderate Covid-19 (Original Article, N Engl J Med 2020;383:2041-2052). The report as published did not provide accurate and complete information on the frequency and duration of previous use of hydroxychloroquine or azithromycin among the trial participants. In the Participants subsection of Methods (page 2), the first sentence should have begun, “We enrolled patients who were either actively screened by the trial team or referred to us who were 18 years of age or older and had been hospitalized …,” rather than “The trial included consecutive patients who were 18 years of age or older and who had been hospitalized ….” In the second sentence, the phrase “previous use of chloroquine, hydroxychloroquine, azithromycin, or any other macrolide for more than 24 hours before enrollment (and since the onset of symptoms)” should have been omitted. In the third sentence, the phrase “, including criteria regarding previous use of hydroxychloroquine or azithromycin,” should have followed the term “exclusion criteria.” In the second paragraph of the Randomization, Interventions, and Follow-up subsection of Methods (page 2), the sentence beginning “The administration of hydroxychloroquine or chloroquine” should have been omitted. In the final footnote below Table 1 (page 4), the phrase “during the 24-hour period” should have been omitted, and the footnote should have ended, “Details are provided in the Supplementary Appendix.” In the Statistical Analysis subsection of Methods, in the final sentence of the paragraph beginning “We also performed …” (page 5), the phrase “during the randomized treatment period” should have been added after “medications received.” In the first paragraph of the Characteristics of the Patients subsection of Results (page 8), “randomization on May 17, 2020” should have been “ … on May 18, 2020.” At the end of that subsection, “Tables S5 and S6, respectively” should have been “Tables S5 through S7.” In the Primary Outcome subsection of Results (page 8), the mentions of Tables S7, S8, and S9, should have been Tables S8, S9, and S10, respectively. The final sentence of that subsection should have ended with “(Table S11) or in three post hoc subgroups defined according to the date of trial enrollment or according to previous use of hydroxychloroquine or azithromycin (Table S12),” rather than “(Table S10).” In the second paragraph of the Secondary Outcomes subsection of Results (page 8), the mentions of Table S11 and Table S12 should have been Table S13 and Table S14. In the final sentence of the Safety subsection of Results (page 9), the mention of Tables S13 and S14 should have been Tables S15 and S16. In the first sentence of the first footnote below Table 3 (page 11), the expression “during the randomized treatment period” should have been added after “according to the medications received.” In the penultimate paragraph of the Discussion (page 11), the sentence beginning, “The enrollment of patients with no previous use of these medications was challenging …” should have been replaced by, “We did not specify in our protocol the exclusion of such patients until late in the course of the trial, and as a consequence, 9.3% of the trial participants had previous use of hydroxychloroquine and 36.1% had previous use of azithromycin. However, in most instances, the duration of previous use was only 24 to 48 hours before enrollment, primarily because, before May 13, we required that patients be enrolled in the trial within 48 hours after hospital admission and because outpatient use of these drugs (before admission) was infrequent. After May 13, we specified that use of these drugs for more than 24 hours was an exclusion criterion.” The Supplementary Appendix was also affected. The article is correct and the Supplementary Appendix has been replaced at NEJM.org.
