Table 2.
Adjusted hazard ratios for COVID-19–associated hospitalization based on Paxlovid prescription receipt (exposure) — Cosmos,∗ United States, April–September 2022.
| Characteristic | Adjusted HR (95% CI)† | No. of participants | No. hospitalized | Events per 100,000 person-days |
||
|---|---|---|---|---|---|---|
| Overall | Exposed§ | Unexposed§ | ||||
| Total | 0.49 (0.46–0.53) | 693,084 | 5,229 | 25.31 | 15.88 | 29.05 |
| COVID-19 vaccination status¶ | ||||||
| Vaccinated (≥3 mRNA doses) | 0.50 (0.45–0.55) | 310,196 | 2,126 | 22.98 | 14.30 | 27.87 |
| Vaccinated (2 mRNA doses) | 0.50 (0.42–0.58) | 149,498 | 1,086 | 24.37 | 16.37 | 26.92 |
| Unvaccinated | 0.50 (0.43–0.59) | 170,789 | 1,477 | 29.05 | 19.60 | 31.08 |
| UHC∗∗ | ||||||
| 0 | 0.89 (0.58–1.36) | 52,592 | 106 | 6.73 | 6.51 | 6.83 |
| 1 | 0.57 (0.45–0.71) | 200,116 | 503 | 8.40 | 6.46 | 9.03 |
| ≥2 | 0.47 (0.44–0.51) | 440,376 | 4,620 | 35.29 | 20.56 | 41.57 |
| Previous infection†† | ||||||
| No | 0.48 (0.44–0.51) | 589,147 | 4,715 | 26.86 | 16.12 | 31.53 |
| Yes | 0.76 (0.60–0.98) | 103,937 | 514 | 16.56 | 13.54 | 17.20 |
| Immunocompromised§§ | ||||||
| No | 0.49 (0.45–0.53) | 628,706 | 3,770 | 20.09 | 12.61 | 23.03 |
| Yes | 0.50 (0.44–0.58) | 64,378 | 1,459 | 77.01 | 45.99 | 90.49 |
| Month of COVID-19 diagnosis | ||||||
| Apr 2022 | 0.54 (0.40–0.71) | 60,001 | 450 | 25.16 | 17.77 | 26.71 |
| May 2022 | 0.57 (0.48–0.67) | 139,062 | 979 | 23.61 | 17.06 | 25.88 |
| Jun 2022 | 0.51 (0.43–0.60) | 143,706 | 1,006 | 23.48 | 15.02 | 26.76 |
| Jul 2022 | 0.46 (0.40–0.53) | 184,153 | 1,432 | 26.09 | 15.65 | 30.94 |
| Aug 2022 | 0.44 (0.38–0.51) | 166,162 | 1,362 | 27.52 | 15.60 | 32.93 |
| Age group, yrs | ||||||
| 18–49 | 0.59 (0.48–0.71) | 275,930 | 886 | 10.73 | 6.99 | 11.68 |
| 50–64 | 0.40 (0.34–0.48) | 211,940 | 1,032 | 16.30 | 7.90 | 20.10 |
| ≥65 | 0.53 (0.48–0.58) | 205,214 | 3,311 | 54.56 | 29.72 | 68.80 |
| By age group, yrs | ||||||
| 18–49 | ||||||
| Vaccinated (≥3 mRNA doses) | 0.75 (0.53–1.06) | 84,054 | 178 | 7.07 | 6.10 | 7.46 |
| Vaccinated (2 mRNA doses) | 0.53 (0.35–0.82) | 70,159 | 198 | 9.43 | 6.20 | 10.16 |
| Unvaccinated | 0.54 (0.39–0.76) | 97,637 | 417 | 14.29 | 9.09 | 15.13 |
| 1 UHC | 0.91 (0.58–1.44) | 109,620 | 157 | 4.78 | 4.11 | 4.91 |
| ≥2 UHC | 0.54 (0.43–0.67) | 166,310 | 729 | 14.67 | 8.35 | 16.54 |
| 50–64 | ||||||
| Vaccinated (≥3 mRNA doses) | 0.41 (0.30–0.55) | 98,699 | 284 | 9.61 | 5.28 | 12.11 |
| Vaccinated (2 mRNA doses) | 0.46 (0.33–0.63) | 47,111 | 265 | 18.84 | 10.96 | 21.89 |
| Unvaccinated | 0.38 (0.27–0.53) | 45,154 | 355 | 26.39 | 12.43 | 30.35 |
| No UHC | 1.11 (0.46–2.68) | 32,519 | 25 | 2.56 | 2.87 | 2.46 |
| 1 UHC | 0.30 (0.17–0.55) | 53,493 | 109 | 6.80 | 2.45 | 8.72 |
| ≥2 UHC | 0.40 (0.33–0.48) | 125,928 | 898 | 23.91 | 11.04 | 30.26 |
| ≥65 | ||||||
| Vaccinated (≥3 mRNA doses) | 0.51 (0.46–0.57) | 127,443 | 1,664 | 44.02 | 24.51 | 57.35 |
| Vaccinated (2 mRNA doses) | 0.53 (0.43–0.65) | 32,228 | 623 | 65.58 | 36.83 | 78.59 |
| Unvaccinated | 0.58 (0.47–0.72) | 27,998 | 705 | 85.92 | 52.75 | 96.15 |
| No UHC | 0.84 (0.51–1.36) | 20,073 | 81 | 13.50 | 10.34 | 15.49 |
| 1 UHC | 0.63 (0.47–0.85) | 37,003 | 237 | 21.47 | 13.66 | 26.77 |
| ≥2 UHC | 0.51 (0.47–0.56) | 148,138 | 2,993 | 68.58 | 37.33 | 85.48 |
Abbreviations: HR = hazard ratio; UHC = underlying health condition.
Cosmos is an electronic health record dataset that includes information from >160 million persons in U.S. health systems covered by Epic. https://cosmos.epic.com
95% CIs that exclude 1 were considered to be statistically significant. Multivariable models were adjusted for age, sex, race and ethnicity, social vulnerability index, number of underlying health conditions, U.S. Census Bureau region of residence, previous infection, and COVID-19 vaccination status, excluding the stratum of interest.
Persons receiving Paxlovid contributed unexposed time until the prescription date and exposed time after the prescription date; those not receiving Paxlovid contributed unexposed time. Follow-up time ended when a hospitalization occurred or at 30-days after diagnosis, whichever came first.
Vaccination categories included 1) unvaccinated if no COVID-19 vaccine had been received; 2) 2 mRNA-dose recipients if ≥14 days had elapsed after the second dose and no subsequent doses had been received or <7 days since receipt of third dose; 3) ≥3 mRNA-dose recipients if ≥7 days had elapsed since receipt of the third dose; and 4) other recipient if any Janssen (Johnson & Johnson) vaccine, other vaccine, or 1 mRNA vaccine dose had been received any time before COVID-19 diagnosis.
https://www.cdc.gov/coronavirus/2019-ncov/hcp/clinical-care/underlyingconditions.html (Accessed October 24, 2022).
Previous infection was defined as a COVID-19 diagnosis code or positive COVID-19 nucleic acid amplification test result or antigen test result >90 days before the current diagnosis.
Immunocompromised status was defined using International Classification of Diseases, Tenth Revision codes (adapted from https://academic.oup.com/cid/article/73/11/e4353/6060064 or immunocompromising medication prescribed during the past 6 months (adapted from https://www.atsjournals.org/doi/10.1513/AnnalsATS.201507-415BC).