Publication date: Nov 10, 2025
Nirmatrelvir-ritonavir is generally recommended to be initiated within five days of COVID-19 symptom onset. This study examined the association between the timing of nirmatrelvir-ritonavir initiation and post-acute outcomes more precisely using territory-wide data in Hong Kong. We included patients aged ≥18 years who tested positive for SARS-CoV-2 between March 16, 2022, and November 9, 2023, and were hospitalized with COVID-19. Treatment groups were formed based on the time from the positive RT-PCR date to nirmatrelvir-ritonavir initiation. Among 15,978 patients who received nirmatrelvir-ritonavir, 10,028 (62. 8%) patients were included in Day 0 group, 4973 (31. 1%) in Day 1 group, and 977 (6. 1%) in Day 2 or later group. The control group comprised 22,312 patients who did not receive nirmatrelvir-ritonavir. Compared with the control group, the risks of post-acute mortality were significantly lower in Day 0 group (hazard ratio [HR] 0. 51, 95% CI 0. 46-0. 56; p
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| Concepts | Keywords |
|---|---|
| Hospitalized | Acute |
| March | Based |
| Nirmatrelvir | Benefits |
| Pcr | Control |
| Covid | |
| Day | |
| Greater | |
| Group | |
| Included | |
| Initiation | |
| Nirmatrelvir | |
| Outcomes | |
| Positive | |
| Post | |
| Ritonavir |
Semantics
| Type | Source | Name |
|---|---|---|
| drug | DRUGBANK | Ritonavir |
| disease | MESH | COVID-19 |
| disease | IDO | symptom |
| disease | MESH | Long Covid |
| drug | DRUGBANK | Guanosine |
| drug | DRUGBANK | (S)-Des-Me-Ampa |
| drug | DRUGBANK | Coenzyme M |
| disease | MESH | death |
| disease | MESH | infection |
| disease | MESH | complications |
| disease | IDO | acute infection |
| drug | DRUGBANK | Methionine |
| drug | DRUGBANK | Dextromethorphan |