Real-World Evidence in the First Round of the United States Inflation Reduction Act Drug Price Negotiations: A Citation Analysis of the Centers for Medicare and Medicaid Services’ Maximum Fair Price Explanation Documents

OBJECTIVES: To quantify and characterize the use of real-world evidence (RWE) in the Centers for Medicare and Medicaid Services (CMS) in the CMS drug pricing negotiations to assess the transparency and methodological consistency of RWE incorporation. METHODS: We extracted and reviewed all 1822 unique citations across the 10 MFP explanation documents available on the CMS's website. For each citation, we identified whether the study constituted RWE, the data source (eg, claims, electronic health records registry/clinical cohort), study design, and whether external health technology assessments were cited. We calculated drug-specific and overall RWE proportions and summarized the methodological features of RWE studies. RESULTS: RWE was cited for all 10 drugs, but its use varied substantially. The share of RWE ranged from 13.8% (Farxiga) to 41.5% (Xarelto). Across all drugs, nearly half of RWE studies used claims/administrative data (47.0%), followed by electronic health record data (17.1%) and registry/clinical cohort data (17.1%). Most RWE studies employed cohort or longitudinal designs (82.1%). Three drugs' citation lists included external health technology assessments HTAs (by the Institute for Clinical and Economic Review or the National Institute for Health and Care Excellence). Despite the broad inclusion of RWE, the maximum fair price documents did not specify how RWE influenced negotiated prices or how CMS evaluated the quality or relevance of these studies. CONCLUSION: These findings underscore the need for greater transparency and consistent methodological standards for evaluating RWE, aligning Medicare's process more closely with international health technology assessment practices.