Is scorpion antivenom cost-effective as marketed in the United States?
OBJECTIVE
The purpose of this study was to analyze the cost-effectiveness of scorpion antivenom compared to no antivenom, in the United States, using a decision analysis framework.


METHODS
A decision analytic model was created to assess patient course with and without antivenom. Costs were determined from the perspective of a health care payer. Cost data used in the model were extracted from Arizona Medicaid. The probability of clinical events occurring with and without antivenom was obtained from the published literature, medical claims obtained from Arizona Medicaid, and results of recent clinical trials. Patients that became so ill that mechanical ventilator support was necessary were considered treatment failures. A Monte Carlo simulation was run 1000 times and sampled simultaneously across all variable distributions in the model.


RESULTS
The mean success rate was 99.87% (95% CI 99.64%-99.98%) with scorpion antivenom and 94.31% (95% CI 91.10%-96.61%) without scorpion antivenom. The mean cost using scorpion antivenom was $10,708 (95% CI $10,556 - $11,010) and the mean cost without scorpion antivenom was $3178 (95% CI $1627 - $5184). Since the 95% CIs do not overlap for either the success or cost, use of the scorpion antivenom was significantly more effective and significantly more expensive than no antivenom. Cost-effectiveness analysis found that the scorpion antivenom was not cost-effective at its current price as marketed in the United States.


CONCLUSIONS
The scorpion antivenom marketed in the United States is extremely effective, but too costly to justify its use in most clinical situations. Formulary committees should restrict the use of this antivenom to only the most severe scorpion envenomations.
Department of Pharmacy Practice and Science, College of Pharmacy, University of Arizona, Tucson, AZ, USA; Venom Immunochemistry, Pharmacology and Emergency Response (VIPER) Institute, College of Medicine, University of Arizona, Tucson, AZ, USA. Electronic address: armstrong@pharmacy.arizona.edu.
Edward P
EP
Armstrong
Maja
M
Bakall
Grant H
GH
Skrepnek
Leslie V
LV
Boyer
D000997:Antivenins / Q000191:economics*; D003365:Costs and Cost Analysis; D003661:Decision Support Techniques; D040541:Marketing; D012604:Scorpion Venoms / Q000276:immunology*; D014481:United States
D000997:Antivenins; D012604:Scorpion Venoms
Cost-effectiveness; Costs; Envenomation; Scorpion antivenom