Cost-effectiveness of outpatient COVID-19 antiviral treatment with nirmatrelvir/ritonavir versus usual care in Swedish patients with various risk factors.

AIMS: Nirmatrelvir/ritonavir (NMV/r) is an orally administered antiviral indicated for the outpatient treatment of adult patients with mild-to-moderate COVID-19 at high risk for disease progression to severe illness. We estimated the cost-effectiveness of NMV/r versus best supportive care for 54 patient cohorts, specified according to age, vaccination status and comorbidity burden.

MATERIALS AND

METHODS

A previously published and validated cost-effectiveness model was utilized and adapted to the Swedish setting. The model used a short-term decision-tree (1 year) followed by a lifetime 2-state Markov model. The short-term decision-tree captured costs and outcomes associated with the primary infection. Post-acute COVID-19 syndrome was only considered in terms of quality-of-life decrements for one year. Baseline hospitalization and mortality risks were taken from a Swedish, nationwide, uniquely granular, Omicron-era, real-world study. NMV/r effectiveness were taken from an Omicron-era US real-world study. Remaining inputs were informed by previous COVID-19 studies and publicly available Swedish sources.

RESULTS

The incremental cost-effectiveness ratios (ICERs) showed a large variation ranging from almost nine million SEK for some of the youngest cohorts to being dominant (i.e. cost-saving with higher gains in quality-of-life vs standard of care) for twelve elderly cohorts. In general, higher age in combination with non-recent (>180 days) or no vaccination led to lower ICERs. Specifically, NMV/r was cost-effective for all but one patient cohorts at least 70 years old, and for most patient cohorts 60-69 years old.

LIMITATIONS: As the COVID-19 landscape changes, symptom burden and baseline risks constantly change. Thus, the cost-effectiveness of NMV/r will change with time. However, the future risks could be related to the risks in the current study, and thus remain useful for decision makers.

CONCLUSIONS

This study shows that NMV/r is a cost-effective or even cost-saving treatment option for many patient cohorts, including most elderly and not-recently vaccinated patients with at least some comorbidity burden.