Clinical effectiveness of nirmatrelvir plus ritonavir for patients with COVID-19 and preexisting psychiatric disorders.

Objectives: This study assessed the clinical effectiveness of the combination of nirmatrelvir and ritonavir (NMV-r) in treating nonhospitalized patients with COVID-19 who have preexisting psychiatric disorders.
Methods: Patients diagnosed with COVID-19 and psychiatric disorders between 1 March 2020, and 1 December 2022, were included using the TriNetX network. The primary outcome was the composite outcome of all-cause emergency department (ED) visits, hospitalization, or death within 30 days.
Results: Propensity score matching yielded two cohorts of 20,633 patients each. The composite outcome of all-cause ED visits, hospitalization, or death within 30 days was 3.57% (737 patients) in the NMV-r cohort and 5.69% (1176) in the control cohort, resulting in a reduced risk in the NMV-r cohort (HR: 0.657; 95% confidence interval (CI): 0.599-0.720). The NMV-r cohort exhibited a lower risk of all-cause hospitalization (HR: 0.385; 95% CI: 0.328-0.451) and all-cause death (HR: 0.110; 95% CI: 0.053-0.228) compared with the control group.
Conclusion: NMV-r could mitigate the risk of adverse outcomes in nonhospitalized patients with COVID-19 and preexisting psychiatric disorders. However, only a limited number of patients in this population received adequate treatment, thus emphasizing the importance of promoting its appropriate use.