Clinical Outcomes Following Treatment for COVID-19 With Nirmatrelvir/Ritonavir and Molnupiravir Among Patients Living in Nursing Homes.

Importance: Older patients living in nursing homes are at very high risk of mortality after getting COVID-19. Objective: To evaluate outcomes following oral antiviral treatment for COVID-19 among nonhospitalized older patients living in nursing homes. Design, Setting, and Participants: This is a territory-wide, retrospective cohort study conducted between February 16 and March 31, 2022, with the last follow-up date on April 25, 2022. Participants were patients with COVID-19 living in nursing homes in Hong Kong. Data analysis was performed from May to June 2022. Exposures: Molnupiravir, nirmatrelvir/ritonavir, or no oral antiviral treatment. Main Outcomes and Measures: The primary outcome was hospitalization for COVID-19, and the secondary outcome was risk of inpatient disease progression (ie, admission to intensive care unit, use of invasive mechanical ventilation, and/or death). Results: Of 14 617 patients (mean [SD] age, 84.8 [10.2] years; 8222 women [56.2%]), 8939 (61.2%) did not use oral antivirals, 5195 (35.5%) used molnupiravir, and 483 (3.3%) used nirmatrelvir/ritonavir. Compared with patients who did not use oral antivirals, those who used molnupiravir and nirmatrelvir/ritonavir were more likely to be female and less likely to have comorbid illnesses and hospitalization in the past year. At a median (IQR) follow-up of 30 (30-30) days, 6223 patients (42.6%) were hospitalized and 2307 patients (15.8%) experienced inpatient disease progression. After propensity score weighting, both molnupiravir and nirmatrelvir/ritonavir were associated with a reduced risk of hospitalization (molnupiravir, weighted hazard ratio [wHR], 0.46; 95% CI, 0.37-0.57; P < .001; nirmatrelvir/ritonavir, wHR, 0.46; 95% CI, 0.32-0.65; P < .001) and inpatient disease progression (molnupiravir, wHR, 0.35; 95% CI, 0.23-0.51; P < .001; nirmatrelvir/ritonavir, wHR, 0.17; 95% CI, 0.06-0.44; P < .001). Nirmatrelvir/ritonavir was comparable to molnupiravir in achieving better clinical outcomes (hospitalization, wHR, 1.00; 95% CI, 0.75-1.33; P = .99; inpatient disease progression, wHR, 0.49; 95% CI, 0.20-1.20; P = .12). Conclusions and Relevance: In this retrospective cohort study, the use of oral antivirals to treat COVID-19 was associated with a reduced risk of hospitalization and inpatient disease progression among patients living in nursing homes. The findings of this study of nursing home residents could be reasonably extrapolated to other frail older patients living in the community.