Cost Effectiveness of Defending Against Bioterrorism

Author: Mira Kim, MPH

Primary Advisor: Noriaki Aoki, MD, PhD (co-author)

Committee Members: Craig Johnson, PhD (co-author); Kim Dunn, MD, PhD (co-author)

Masters thesis, The University of Texas School of Health Information Sciences at Houston.

Background: Inhalational anthrax has been classified by the U.S. Centers for Disease Control and Prevention (CDC) as one of six “category A” bioterrorist agents posing the highest risk to the population. Objective: To evaluate the cost effectiveness strategies for treatment of an aerosolized Bacillus anthracis bioterrorist attack.
Design: Decision analytic model
Data sources: We derived probabilities of anthrax exposure, diagnostic characteristics, their costs and associated clinical outcomes from the published literature.
Intervention: We evaluated six post-attack strategies: Treat all, Treat all pending culture, Three tests (Influenza test, chest x ray examination, blood culture), two tests (chest x ray and blood culture), Treat none pending culture, Treat none.
Outcome Measures: Costs, survival rates, and incremental cost-effectiveness
Results of Sensitivity analysis: If an aerosolized B. anthracis bio-weapon attack occurs, “Treat all pending culture” strategy tends to have higher survival rate and lower cost compared with other strategies when the prevalence of inhalational anthrax is 10% and patients have symptom of dyspnea and nausea/vomiting. If the sensitivity of chest x-ray is 0.97 or higher, “Three tests” is optimal strategy and the mortality of antibiotic adverse effect is 0.00125 or higher, “Three tests / Two tests” was optimal option. When the prevalence of inhalational anthrax is 0.1 or less, screening is preferred regardless of the availability of antibiotics. In addition, if the availability of antibiotics is more than 30% and the prevalence of anthrax become higher, treat all strategy is preferred while screening strategy is preferred when the prevalence of anthrax is less than 10%.
Conclusions: In the event of an aerosolized B. anthracis bio-weapon attack, a “Treat all pending culture” strategy generated a higher survival rate and lower cost compared with other strategies. By using the best available current data, our analysis allows clinicians and public health officials to weigh the risks and benefits of alternative treatment strategies for patients with influenza-like symptoms and possible, but not definite, exposure to anthrax.