The answer–according to a recent study by Thornton Snider et al. (2019)–is not that easy. Using case studies of ICER report’s predictions of unmanaged uptake of new medications before 2016, the paper estimates how well these reports predict price, uptake, and overall spending. The authors find:
ICER’s uptake estimates exceeded real-world estimates by factors ranging from 7.4 (sacubitril/valsartan) to 54 (hepatitis C treatments). The “unmanaged uptake” assumption (removed from ICER’s approach in 2017) yields large deviations between BIM estimates and real-world consumption. Nevertheless, in some cases, ICER’s BIMs that relied on current market estimates also deviated substantially from real-world sales data.
Overall, ICER’s price estimates were not too far off, typically 15%-24% higher than actual prices. However, the unmanaged uptake assumption meant that utilization estimates were off by 2500% for new drugs and even by 760% for drugs already in the market. Combining these affects, total spending on these medications was overestimated by a factor or 36 for new treatments, and by a factor of 8.6 for drugs already in the market.
Source:
- Snider JT, Sussell J, Tebeka MG, Gonzalez A, Cohen JT, Neumann P. Challenges with Forecasting Budget Impact: A Case Study of Six ICER Reports. Value in Health. 2019 Mar 1;22(3):332-9.