Potential implications of increased utilization of oral nirmatrelvir/ritonavir in outpatient care for COVID-19: modeled findings from the Spanish National Health System perspective

INTRODUCTION: This analysis evaluates the clinical and societal impact of increasing utilization of oral nirmatrelvir/ritonavir (NMV/r) for outpatient treatment of mild-to-moderate COVID-19 among high-risk adults in Spain. Despite strong evidence from clinical trials and real-world studies demonstrating NMV/r's effectiveness in reducing hospitalization and death, uptake in Spain has remained suboptimal. METHODS: Using a decision tree adapted from a previously published model, we estimated outcomes from the perspective of the Spanish National Health System over a 30-day time horizon. Model inputs included Spanish epidemiological data, healthcare resource utilization rates, and productivity loss parameters. Five NMV/r uptake scenarios were compared: current utilization (30.9%), three hypothetical increased utilization rates (45%, 60%, 75%), and a 0% utilization scenario. RESULTS: Results indicate that increasing NMV/r uptake substantially reduces hospitalizations, ICU admissions, and mortality, while improving productivity outcomes. Compared with the base case, hospitalizations and deaths declined by 15-47% and productivity loss hours by 15-45% across higher utilization scenarios; conversely, the 0% scenario resulted in a 33% increase in hospitalizations and a 32% rise in productivity loss. Sensitivity analyses confirmed the robustness of findings across key parameters. These results underscore the clinical and societal benefits of broader NMV/r adoption and provide timely, policy-relevant evidence to inform strategies that enhance treatment uptake. CONCLUSIONS: Greater utilization of NMV/r could alleviate strain on the Spanish health system and prevent avoidable hospitalizations and deaths, reinforcing the importance of interventions that promote timely access for high-risk patients.