ABSTRACT
Budget impact analysis (BIA) provides a framework to compare the impact on annual condition-related expenditures of adding a new intervention to the current treatment mix for those who are indicated for the new intervention. The steps involved in performing a BIA include estimating the indicated population size, estimating the current treatment mix and the changes in the treatment mix, and estimating the changes in condition-related costs over the model time horizon with and without the addition of the new intervention. The model time horizon is generally limited to 3–5 years. The model structure should be as simple as possible; four example model structures are included in this chapter. Input data include those required for cost-effectiveness analyses as well as data on the size and condition severity mix of the indicated population. The model should be validated using data on current expenditures for the condition of interest and should be designed to allow extensive scenario analyses to generate estimates that are relevant for different budget holders. Some discussion of how the affordability of estimated budget impacts of a single intervention or multiple interventions might be determined is included in the chapter.
