Health outcomes and costs of community mitigation strategies for an influenza pandemic in the United States.

BACKGROUND: The optimal community-level approach to control pandemic influenza is unknown.
METHODS: We estimated the health outcomes and costs of combinations of 4 social distancing strategies and 2 antiviral medication strategies to mitigate an influenza pandemic for a demographically typical US community. We used a social network, agent-based model to estimate strategy effectiveness and an economic model to estimate health resource use and costs. We used data from the literature to estimate clinical outcomes and health care utilization.
RESULTS: At 1% influenza mortality, moderate infectivity (R(o) of 2.1 or greater), and 60% population compliance, the preferred strategy is adult and child social distancing, school closure, and antiviral treatment and prophylaxis. This strategy reduces the prevalence of cases in the population from 35% to 10%, averts 2480 cases per 10,000 population, costs $2700 per case averted, and costs $31,300 per quality-adjusted life-year gained, compared with the same strategy without school closure. The addition of school closure to adult and child social distancing and antiviral treatment and prophylaxis, if available, is not cost-effective for viral strains with low infectivity (R(o) of 1.6 and below) and low case fatality rates (below 1%). High population compliance lowers costs to society substantially when the pandemic strain is severe (R(o) of 2.1 or greater).
CONCLUSIONS: Multilayered mitigation strategies that include adult and child social distancing, use of antivirals, and school closure are cost-effective for a moderate to severe pandemic. Choice of strategy should be driven by the severity of the pandemic, as defined by the case fatality rate and infectivity.