Table 1 Baseline characteristics of nirmatrelvir/ritonavir users who initiated early (day 0–1) and late (days ≥ 2) in (a) mortality or hospitalization analysis and (b) viral burden rebound analysis
(a) Mortality or hospitalization analysis | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Before IPW | After IPW | |||||||||
Baseline characteristics | Day 0–1 (N = 43,625) | Days ≥2 (N = 43,445) | SMD | Day 0–1 (N = 43,625) | Days ≥2 (N = 43,445) | SMD | ||||
N/mean | %/SD | N/mean | % / SD | %/mean | %/SD | %/mean | %/SD | |||
Age, years | 62.6 | 14.4 | 61.0 | 15.1 | 0.11 | 61.8 | 14.7 | 61.8 | 14.9 | 0.00 |
18–40 | 4232 | 9.7% | 5200 | 12.0% | 0.09 | 10.9% | 10.7% | 0.02 | ||
41–65 | 19,267 | 44.2% | 19,812 | 45.6% | 45.5% | 44.7% | ||||
>65 | 20,126 | 46.1% | 18,433 | 42.4% | 43.5% | 44.6% | ||||
Sex | ||||||||||
Male | 19,218 | 44.1% | 18,486 | 42.6% | 0.03 | 43.5% | 43.7% | 0.00 | ||
Female | 24,407 | 55.9% | 24,959 | 57.4% | 56.5% | 56.3% | ||||
Regions | ||||||||||
Hong Kong Island | 7446 | 17.1% | 7369 | 17.0% | 0.01 | 17.0% | 17.1% | 0.00 | ||
Kowloon | 11,422 | 26.2% | 11,560 | 26.6% | 26.3% | 26.2% | ||||
New Territories | 24,718 | 56.7% | 24,469 | 56.3% | 56.6% | 56.6% | ||||
Others | 39 | 0.1% | 47 | 0.1% | 0.1% | 0.1% | ||||
Charlson’s index | 2.7 | 1.4 | 2.6 | 1.4 | 0.10 | 2.7 | 1.4 | 2.7 | 1.4 | 0.01 |
0–4 | 42,202 | 96.7% | 41,828 | 96.3% | 0.03 | 96.6% | 95.9% | 0.03 | ||
5–6 | 1203 | 2.8% | 1,371 | 3.2% | 2.9% | 3.4% | ||||
7–14 | 220 | 0.5% | 246 | 0.6% | 0.5% | 0.6% | ||||
Symptomatic presentation | 29,159 | 66.8% | 39,615 | 91.2% | 0.63 | 79.0% | 78.9% | 0.00 | ||
Concomitant corticosteroid use | 425 | 1.0% | 499 | 1.1% | 0.02 | 1.1% | 1.2% | 0.01 | ||
Immunocompromised | 603 | 1.4% | 720 | 1.7% | 0.02 | 1.6% | 1.7% | 0.00 | ||
Healthcare utilization | 1,761 | 4.0% | 1,878 | 4.3% | 0.01 | 4.4% | 4.7% | 0.01 | ||
Previous SARS-CoV-2 infection | 90 | 0.2% | 29 | 0.1% | 0.04 | 0.1% | 0.1% | 0.00 | ||
COVID-19 vaccination status* | ||||||||||
Not fully vaccinated | 5073 | 11.6% | 5661 | 13.0% | 0.05 | 12.5% | 12.7% | 0.01 | ||
Fully vaccinated but not boosted | 14,883 | 34.1% | 14,966 | 34.4% | 34.3% | 34.4% | ||||
Boosted | 23,669 | 54.3% | 22,818 | 52.5% | 53.2% | 53.0% | ||||
Time of SARS-CoV-2 infection diagnosis | ||||||||||
March–June 2022‡ | 2900 | 6.6% | 2753 | 6.3% | 0.03 | 6.6% | 6.8% | 0.01 | ||
July–October 2022‡ | 16,639 | 38.1% | 17,119 | 39.4% | 38.9% | 39.0% | ||||
November 2022–January 2023‡ | 24,086 | 55.2% | 23,573 | 54.3% | 54.5% | 54.2% | ||||
Day of the week of SARS-CoV-2 infection diagnosis | ||||||||||
Sunday | 6084 | 13.9% | 6136 | 14.1% | 0.02 | 14.0% | 14.3% | 0.02 | ||
Monday | 5812 | 13.3% | 5929 | 13.6% | 13.4% | 13.6% | ||||
Tuesday | 5649 | 12.9% | 5608 | 12.9% | 13.0% | 12.7% | ||||
Wednesday | 6316 | 14.5% | 6185 | 14.2% | 14.4% | 14.4% | ||||
Thursday | 6751 | 15.5% | 6549 | 15.1% | 15.4% | 15.0% | ||||
Friday | 6602 | 15.1% | 6441 | 14.8% | 15.2% | 14.9% | ||||
Saturday | 6411 | 14.7% | 6597 | 15.2% | 14.6% | 15.0% | ||||
Day of the week of SARS-CoV-2 infection diagnosis | ||||||||||
Weekend | 12,495 | 28.6% | 12,733 | 29.3% | 0.01 | 28.6% | 29.4% | 0.02 | ||
Weekdays | 31,130 | 71.4% | 30,712 | 70.7% | 71.4% | 70.6% | ||||
Type of viral test for case detection | ||||||||||
Rapid antigen test | 30,957 | 71.0% | 31,833 | 73.3% | 0.05 | 72.2% | 72.4% | 0.01 | ||
RT-qPCR | 12,668 | 29.0% | 11,612 | 26.7% | 27.8% | 27.6% | ||||
(b) Viral burden rebound analysis | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Before IPW | After IPW | |||||||||
Baseline characteristics | Day 0–1 (N = 9,128) | Days ≥2 (N = 541) | SMD | Day 0–1 (N = 9128) | Days ≥2 (N = 541) | SMD | ||||
N/mean | %/SD | N/mean | %/SD | %/mean | %/SD | %/mean | %/SD | |||
Age, years | 73.0 | 15.2 | 69.4 | 17.0 | 0.24 | 72.8 | 15.3 | 72.5 | 15.6 | 0.02 |
18–40 | 412 | 4.5% | 48 | 8.9% | 0.21 | 4.7% | 5.5% | 0.04 | ||
41–65 | 1824 | 20.0% | 126 | 23.3% | 20.2% | 19.2% | ||||
>65 | 6892 | 75.5% | 367 | 67.8% | 75.0% | 75.3% | ||||
Sex | ||||||||||
Male | 4837 | 53.0% | 296 | 54.7% | 0.03 | 53.1% | 53.8% | 0.01 | ||
Female | 4291 | 47.0% | 245 | 45.3% | 46.9% | 46.2% | ||||
Regions | ||||||||||
Hong Kong Island | 1867 | 20.5% | 104 | 19.2% | 0.07 | 20.4% | 19.8% | 0.02 | ||
Kowloon | 2526 | 27.7% | 145 | 26.8% | 27.6% | 28.1% | ||||
New Territories | 4693 | 51.4% | 287 | 53.0% | 51.5% | 51.6% | ||||
Others | 42 | 0.5% | 5 | 0.9% | 0.5% | 0.5% | ||||
Charlson’s index | 4.6 | 1.8 | 4.3 | 2.1 | 0.16 | 4.5 | 1.8 | 4.5 | 1.9 | 0.01 |
0–4 | 4270 | 46.8% | 285 | 52.7% | 0.13 | 47.1% | 48.0% | 0.04 | ||
5–6 | 3808 | 41.7% | 193 | 35.7% | 41.5% | 39.5% | ||||
7–14 | 1050 | 11.5% | 63 | 11.6% | 11.4% | 12.4% | ||||
Symptomatic presentation | 968 | 10.6% | 74 | 13.7% | 0.09 | 10.8% | 10.5% | 0.01 | ||
Inpatient users | 8861 | 97.1% | 519 | 95.9% | 0.06 | 97.0% | 97.1% | 0.01 | ||
Concomitant corticosteroid use | 1976 | 21.6% | 128 | 23.7% | 0.05 | 21.8% | 22.9% | 0.02 | ||
Immunocompromised | 2112 | 23.1% | 108 | 20.0% | 0.08 | 23.0% | 23.6% | 0.01 | ||
Healthcare utilization | 6045 | 66.2% | 342 | 63.2% | 0.06 | 66.1% | 65.5% | 0.01 | ||
Previous SARS-CoV-2 infection | 1294 | 14.2% | 77 | 14.2% | 0.00 | 14.2% | 14.8% | 0.02 | ||
COVID-19 vaccination status* | ||||||||||
Not fully vaccinated | 2,762 | 30.3% | 197 | 36.4% | 0.13 | 30.6% | 31.5% | 0.02 | ||
Fully vaccinated but not boosted | 4,028 | 44.1% | 216 | 39.9% | 43.9% | 42.7% | ||||
Boosted | 2,338 | 25.6% | 128 | 23.7% | 25.5% | 25.8% | ||||
Time of SARS-CoV-2 infection diagnosis | ||||||||||
March–June 2022‡ | 697 | 7.6% | 100 | 18.5% | 0.33 | 8.3% | 8.7% | 0.03 | ||
July–October 2022‡ | 4495 | 49.2% | 250 | 46.2% | 49.1% | 47.7% | ||||
November 2022–January 2023‡ | 3936 | 43.1% | 191 | 35.3% | 42.7% | 43.6% | ||||
Day of the week of SARS-CoV-2 infection diagnosis | ||||||||||
Sunday | 1314 | 14.4% | 68 | 12.6% | 0.19 | 14.4% | 13.5% | 0.20 | ||
Monday | 1322 | 14.5% | 67 | 12.4% | 14.5% | 11.6% | ||||
Tuesday | 1260 | 13.8% | 68 | 12.6% | 13.8% | 12.4% | ||||
Wednesday | 1273 | 13.9% | 70 | 12.9% | 14.0% | 13.1% | ||||
Thursday | 1350 | 14.8% | 70 | 12.9% | 14.8% | 12.5% | ||||
Friday | 1349 | 14.8% | 89 | 16.5% | 14.8% | 16.9% | ||||
Saturday | 1260 | 13.8% | 109 | 20.1% | 13.8% | 20.0% | ||||
Day of the week of SARS-CoV-2 infection diagnosis | ||||||||||
Weekend | 2574 | 28.2% | 177 | 32.7% | 0.10 | 28.2% | 33.5% | 0.12 | ||
Weekdays | 6554 | 71.8% | 364 | 67.3% | 71.8% | 66.5% | ||||
Type of viral test for case detection | ||||||||||
Rapid antigen test | 725 | 7.9% | 26 | 4.8% | 0.13 | 7.8% | 8.6% | 0.03 | ||
RT-qPCR | 8403 | 92.1% | 515 | 95.2% | 92.2% | 91.4% | ||||
Presence of at least one Ct value measurement within five days from diagnosis or symptom onset | 8483 | 92.9% | 506 | 93.5% | 0.02 | 93.0% | 93.3% | 0.01 | ||
