title: A Methodological Review of US Budget-Impact Models for New Drugs.
abstract: A budget-impact analysis is required by many jurisdictions when adding a new drug to the formulary. However, previous reviews have indicated that adherence to methodological guidelines is variable. In this methodological review, we assess the extent to which US budget-impact analyses for new drugs use recommended practices. We describe recommended practice for seven key elements in the design of a budget-impact analysis. Targeted literature searches for US studies reporting estimates of the budget impact of a new drug were performed and we prepared a summary of how each study addressed the seven key elements. The primary finding from this review is that recommended practice is not followed in many budget-impact analyses. For example, we found that growth in the treated population size and/or changes in disease-related costs expected during the model time horizon for more effective treatments was not included in several analyses for chronic conditions. In addition, all drug-related costs were not captured in the majority of the models. Finally, for most studies, one-way sensitivity and scenario analyses were very limited, and the ranges used in one-way sensitivity analyses were frequently arbitrary percentages rather than being data driven. The conclusions from our review are that changes in population size, disease severity mix, and/or disease-related costs should be properly accounted for to avoid over- or underestimating the budget impact. Since each budget holder might have different perspectives and different values for many of the input parameters, it is also critical for published budget-impact analyses to include extensive sensitivity and scenario analyses based on realistic input values.
authors.affiliation: RTI Health Solutions, 3040 Cornwallis Road, Post Office Box 12194, Research Triangle Park, NC, 27709-2194, USA. jmauskopf@rti.org.
authors.forename: Josephine
authors.initials: J
authors.lastname: Mauskopf
authors.affiliation: RTI Health Solutions, 3040 Cornwallis Road, Post Office Box 12194, Research Triangle Park, NC, 27709-2194, USA.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Earnshaw
mesh_terms: D002017:Budgets; D016527:Drug Costs; D005569:Formularies as Topic; D019983:Guideline Adherence; D017408:Guidelines as Topic; D006801:Humans; D018803:Models, Economic; D004364:Pharmaceutical Preparations / Q000008:administration & dosage / Q000191:economics; D014481:United States
chemical_list: D004364:Pharmaceutical Preparations