Outcomes
Crude analysis showed that the duration of oxygen-support requirement in therapy groups had no significant differences compared to standard care group (median, 13 days [interquartile range:8, 16], 11 days [interquartile range:7, 22] vs 13 days [interquartile range:7, 24]; P = 0.98; Table 3). Meanwhile, there was no difference in virus clearance time among 3 groups. Using Cox proportional hazards regression adjusting for baseline covariate, there was no significant association of Kaletra /interferon alfa-2b with faster SARS-CoV-2 RNA clearance (HR, 0.85 [95% CI, 0.45–1.61]; P = 0.61 in interferon alfa-2b group vs HR, 0.59 [95% CI, 0.32–1.11]; P = 0.10 in Kaletra plus interferon alfa-2b group, Table 4, Figure 2). The duration of oxygen-support requirement in therapy groups similarly showed no significant association (HR, 1.46 [95% CI, 0.57–3.75]; P = 0.43 in interferon alfa-2b group vs HR, 1.06 [95% CI, 0.43–2.63]; P= 0.90 in Kaletra plus interferon alfa-2b group, Table 4, Figure 3).