OBJECTIVES: The purpose was to estimate the EI of VM in the US from payer and societal perspectives. METHODS: The EI of VM was estimated by applying the cost and probability estimates of events in a decision analytic framework (DAF). DAF development and probability of events were obtained from an expert panel. Direct medical costs were estimated by charge data obtained from the 1996 Pennsylvania Medicaid database and the Drug Topics Red Book. Indirect costs were obtained in terms of activity restricted days (ARDs) as estimated by the panel. ARDs were defined as the average number of days patients with VM missed school/work or normal activities. Monte Carlo simulations were used to generate the distribution of charges for estimating the EI of VM on a per patient basis. The per patient EI was then extrapolated to the US population. Sensitivity analyses (one-way) were conducted by varying the probability values at the dominant nodes, nodes with high-cost, and nodes with the largest ranges. RESULTS: An episode of VM poses direct medical costs to payers ranging from $4,500-$5,700 in adult patients and $5,000-$5,300 in pediatric patients. Similarly, an episode of VM poses an average of 5.6-7.5 ARDs. These results were stable across the sensitivity parameters tested. CONCLUSIONS: Management of VM imposes a sizable economic burden from both the payer and societal perspectives. Based on a conservatively estimated 250,000 annual cases of VM in the US, the economic burden to payers in terms of direct costs exceeds $1 billion per year. The additional economic burden in terms of indirect costs to society would approximate 1.5 million ARDs.