Cost comparison of F(ab’) 2 and Fab antivenoms for pit viper envenomation in the United States: a real-world analysis

Background This study compared healthcare resource utilization (HCRU) and cost among patients treated for pit viper envenomation with Fab or F(ab’)2 antivenom in the United States.Research design and methods Patients administered Fab or F(ab’)2 between January 2019 and September 2022 were identified from IQVIA’s New Data Warehouse and placed into two mutually exclusive cohorts. Inverse probability of treatment weighting (IPTW) was used to adjust for baseline differences between cohorts. All-cause HCRU and cost were assessed in the 6-months following antivenom administration (post-index) and compared between IPTW-adjusted cohorts.Results In total, 242 and 98 patients receiving Fab and F(ab’)2 were identified, respectively. Pre-IPTW adjustment, cohorts differed on demographics and select comorbidities (standardized mean difference [SMD] ≥0.10). Post-IPTW, most variables were balanced (SMD < 0.01). Post-index total (Fab: $70,994; F(ab’)2: $55,324), medical ($69,162; $52,339), and inpatient costs ($49,466; $29,730) were higher among Fab than F(ab’)2 patients (all p < 0.05). After multivariable adjustment, the total (cost ratio [CR]: 0.83; 95% confidence interval [CI]: 0.70–0.98), inpatient (CR: 0.63; 95% CI: 0.51–0.79), and inpatient pharmacy costs (CR: 0.48; 95% CI: 0.33–0.68) were lower in the F(ab’)2 than Fab cohort.Conclusions Patients administered Fab had higher post-index total, inpatient, and inpatient pharmacy costs than patients administered F(ab’)2 AV.