ABSTRACT
OBJECTIVES: This study investigated the outcomes of underweight patients with COVID-19 and the effectiveness of antiviral agents in this population. METHODS: A retrospective cohort study using theTriNetX research network was conducted. Propensity score matching (PSM) was employed to balance the first cohort involving COVID-19 patients with underweight and normal-weight. In the second cohort, underweight patients receiving antiviral agents and untreated individuals were matched using PSM. The primary outcome was a composite of all-cause hospitalization and death during the 7-30-day follow-up period. RESULTS: After PSM, the first cohort including each group of 13,502 patients with balanced baseline characteristics were identified for comparing the outcome of patients with underweight and normal weight. The underweight group had a higher risk of the composite primary outcome than those with normal weight (hazard ratio [HR], 1.251; 95% confidence interval [CI], 1.132-1.382). The second cohort included each 884 underweight patients with and without receiving antivirals.Compared with untreated patients, those receiving antiviral treatment had a lower risk of composite primary outcomes (HR, 0.426; 95% CI, 0.278-0.653). CONCLUSION: Underweight status may be associated with a higher risk of all-cause hospitalization and death in patients with COVID-19.Among underweight patients, antiviral agents demonstrated clinically beneficial effects.