Pulmonology Advisor Real-world evidence from the Omicron period of the COVID-19 pandemic shows the benefit of nirmatrelvir-ritonavir for vaccinated outpatients and those younger than 65 years of age with non-severe COVID-19 at high risk of hospitalization or death, according to study findings published in The Lancet Infectious Diseases.
Investigators sought to examine the real-world effect of nirmatrelvir-ritonavir treatment on emergency department visits, 28-day hospitalization, and mortality among outpatients with early symptomatic COVID-19 during a SARS-CoV-2 Omicron predominant (BA.2, BA2.12.1, BA.4, and BA.5) period. The primary endpoint was 28-day all-cause hospitalization.
This propensity-matched, retrospective, observational cohort study of non-hospitalized adult patients infected with SARS-CoV-2 was conducted from March 2022 through August 2022. Investigators analyzed data from electronic health records from the University of Colorado Health (a 13-hospital system with 141,000 annual admissions and numerous ambulatory sites and affiliated pharmacies). The analysis included data from outpatients with a nirmatrelvir-ritonavir order or a positive SARS-CoV-2 test; those treated with nirmatrelvir-ritonavir were propensity score matched with patients who were untreated.
A total of 21,493 patients infected with SARS-CoV-2 between the last week in March and the last week in August 2022 met inclusion criteria; 11,612 were untreated and 9881 received nirmatrelvir–ritonavir treatment (300 mg nirmatrelvir [150 mg with moderate renal impairment] and 100 mg ritonavir orally, twice daily, for 5 days). Because most of those who received nirmatrelvir-ritonavir treatment did not have a positive SARS-CoV-2 test in their electronic health records, and nirmatrelvir-ritonavir prescription requires a positive SARS-CoV-2 test, investigators assumed testing occurred outside the health system.
The 16,529 patients in the propensity matched cohort were stratified by age (ie, <65 years and ≥65 years), sex, number of vaccinations at time of infection, obesity status, immunocompromised status, number of comorbid conditions other than obesity and immunocompromised status, and race and ethnicity (ie, non-Hispanic White vs other). Significant baseline differences in characteristics in the treatment cohort vs the control cohort included older age, higher rate of Medicare insurance, and more participants with 2 or more comorbidities. Among patients in the treatment group, 26.8% were obese, 24.6% were immunocompromised, 32.1% were at least 65 years of age, 30.5% had at least 2 additional comorbid conditions, 20.4% had no vaccinations prior to their positive SARS-CoV-2 test, and 60.7% had at least 3 vaccinations prior to a positive test.