Application of nirmatrelvir-ritonavir for primary and secondary
outcomes
The mean time from symptom onset or the first positive RT-PCR result to
negative RT-PCR results was similar in both the treatment and control
groups (16.2±5.0 vs. 16.1±6.3 days, P = 0.83, Table 2). Figure 2
displays the Kaplan-Meier survival curve for the primary outcome. No
correlation was observed between the time to conversion of RT-PCR
results and patients’ age, clinical classification, concurrent
medication usage, or prior vaccination in the analysis of individuals
treated with nirmatrelvir-ritonavir, except in the case of the usage of
antibiotics (Figure 4). Following the appearance of symptoms or the
initial RT-PCR confirmation, 92% of nirmatrelvir-ritonavir was
administered within 14 days, while 82% and 64% were taken within 10
and 7 days respectively (Figure 3).
Hence, the subgroup analysis was
further stratified based on the time interval between the administration
of nirmatrelvir-ritonavir and the onset of symptoms or the first
positive RT-PCR test. Patients who received nirmatrelvir-ritonavir
within 10 days of experiencing symptoms demonstrated quicker conversion
of RT-PCR results compared to the control group that was matched (Figure
5).
No significant difference was found between the two groups in the
percentage of patients who tested negative for respiratory SARS-CoV-2
using RT-PCR 15 days after the onset of symptoms (47.2% vs 50.0%,
P=0.53). Additionally, the two groups did not differ significantly with
respect to the progression to more severe conditions, such as turning to
critically ill (1.9% vs 1.9%, P = 1), need for mechanical ventilation
(0.3% vs 1.5%, P = 0.21), and the need for oxygen therapy (2.5% vs
3.4%, P = 0.64).