Availability of Cost-effectiveness Studies for Drugs With High Medicare Part D Expenditures

Importance Prescription drug spending in the US requires policy intervention to control costs and improve the value obtained from pharmaceutical spending. One such intervention is to apply cost-effectiveness evidence to decisions regarding drug coverage and pricing, but this intervention depends on the existence of such evidence to guide decisions. Objective To characterize the availability and quality of cost-effectiveness studies for prescription drugs with the greatest Medicare Part D spending. Design, setting, and participants In this national cross-sectional analysis, publicly available 2016 Medicare drug spending records were merged with 2016 US Food & Drug Administration Orange Book data and the Tufts Medical Center Cost-Effectiveness Analysis (CEA) Registry. All studies published through 2015 that evaluated the cost-effectiveness of the 250 drugs for which Medicare Part D spending was the greatest in US-based adult patient populations were included. Data were analyzed from September 2018 to June 2020. Main outcomes and measures The presence and quality of published cost-effectiveness analyses for the 250 drugs for which Medicare Part D spending was greatest in 2016 were assessed based on the inclusion of key cost-effectiveness analysis elements and global ratings by independent reviewers for the Tufts CEA Registry. Results Medicare Part D spending on the 250 drugs in the sample totaled $122.8 billion in 2016 (84.1% of total spending). Of these 250 drugs, 91 (36.4%) had a generic equivalent and 159 (63.6%) retained some patent exclusivity. There were 280 unique cost-effectiveness analyses for these drugs, representing data on 135 (54.0%) of the 250 drugs included and 67.0% of Part D spending on the top 250 drugs. The 115 drugs (46.0%) without cost-effectiveness studies accounted for 33.0% of Part D spending on the top 250 drugs. Of the 280 available studies, 128 (45.7%) were industry sponsored. A large proportion of the studies (250 [89.3%]) did not meet the minimum quality requirements. Conclusions and relevance In this cross-sectional study, a substantial proportion of 2016 Medicare Part D spending was for drugs with absent or low-quality cost-effectiveness analyses. The lack of quality analyses may present a challenge in efforts to develop policies addressing drug spending in terms of value.