Analysis of the effectiveness of nirmatrelvir plus ritonavir. (A) Subgroup analysis of the differences of the proportions of patients treated within 5 days of positive PCR who had COVID-19–related hospitalization or death from any cause through day 35. (B) Cumulative HR by COVID-19 antiviral therapy. For patients who received treatment with antiviral agents, time zero corresponded to the time at which a patient began the treatment. For patients who did not receive treatment with either nirmatrelvir or molnupiravir, time zero corresponded to the time at which each patient had received a positive COVID-19 PCR. Setting time zero to the time at which each patient had received a positive COVID-19 PCR for both patients who received and did not receive treatment, yields similar results (supplemental Figure 3). Cumulative HR curve disregards 2 patients who did not receive treatment for whom the exact event time could not be determined. The shaded areas indicate the 95% CI.