Table 2 details the cost-benefit ratios of the competing strategies. Based on the historic incidence of 3 influenza pandemics over the last century, we adjusted all cost-benefit outcomes for a conservatively estimated probability of 3 pandemics every 100 years and applied a wide range of estimates for sensitivity analyses (Appendix). We compared the economic outcomes of each of the 5 strategies with nonintervention, estimated stockpiling costs, and calculated cost-benefit ratios. Oseltamivir stockpiling costs were calculated with prices quoted in March 2004 by the manufacturer's representative in Israel for uncapsulated, water-soluble, bulk active powder with a 10-year shelf life.

Oseltamivir was selected as the drug of choice, at a daily dosage of 75 mg for prophylaxis and 150 mg for treatment ( 7). The cost of each strategy was calculated by multiplying the estimated number of treated persons by the discounted cost of a single antiviral course. Briefly, the economic benefit of each strategy was calculated by multiplying each of the reductions in adverse outcomes by its estimated economic value. The impact of each strategy on health-related outcomes was analyzed in a spreadsheet model by using the formulas summarized in Figure A1. Systematic review and meta-analysis were used to estimate the efficacy of preexposure prophylaxis, while the expected efficacy of postexposure prophylaxis and the number of persons treated under this strategy were estimated by using the results of a recently published stochastic simulation model ( 6). The efficacy of therapeutic treatment was based on currently available evidence regarding epidemic influenza (Appendix). The first 2 strategies could target either the entire population or only those at high risk for complications. We defined 3 strategies for the use of antiviral drugs during a pandemic: therapeutic use, long-term preexposure prophylaxis, and short-term postexposure prophylaxis for close contacts of influenza patients (with index patients under treatment). These outcomes would result in an excess of $55.4 million in health-related costs and in overall costs to the economy of $523.5 million (≈0.5% of the Israeli gross domestic product). †Population attack rate was calculated by stratifying the population by age and risk and applying age- and risk-specific attack rates and ranges (Appendix).Īccording to base-case assumptions, a pandemic would result in an estimated 1,618,200 patients (≈25% of the Israeli population), 781,921 physician visits, 10,334 hospitalizations, 2,855 deaths, and 6,536,240 lost workdays. *Complete list and references available in online Appendix. We set out to identify strategies for the use of the antiviral drug oseltamivir in the containment of a pandemic and to construct a mathematical model to appraise the cost and benefit of each strategy in terms of health-related and economic outcomes. The Israeli Ministry of Health appointed a working group to address national preparation for an influenza pandemic. However, the cost-benefit of stockpiling has yet to be assessed, and the optimal strategy for antiviral use is still under debate.

The World Health Organization recently encouraged health authorities to consider stockpiling antiviral drugs in anticipation of a pandemic ( 3). The next pandemic will be associated with major adverse health and economic outcomes, with estimated costs reaching US$166 billion in the United States alone ( 2). As the epidemic grows, so does the probability that this virulent virus will acquire genetic traits for increased person-to-person transmissibility, potentially setting the stage for the next global influenza pandemic ( 1). The widespread epidemic of highly pathogenic avian influenza that emerged in east Asia continues today.

Define stockpile pills