In this chapter, we discuss how to estimate any changes in condition-related costs and outcomes that might be expected to occur as a result of the introduction of the new drug to the formulary. These changes should be included in the budget-impact estimates if they are likely to occur within the analysis time horizon and if there are credible clinical data that indicate that such changes are likely.Condition-related costs and outcomes that occur beyond the analysis time horizon may also be important to consider within an analysis.Consideration of these costs along with condition-related costs and outcomes that might occur for an incident versus a prevalent population are discussed.
