Citation Analysis of Real-World Evidence in Medicare Drug Price Negotiations
Medicare Drug Price Negotiations are increasingly relying on real-world evidence, according to a new citation analysis of the first drugs selected under the Inflation Reduction Act. The study examined how the Centers for Medicare and Medicaid Services (CMS) uses real-world evidence (RWE) in its Maximum Fair Price (MFP) Explanation documents for the initial ten drugs.
RWE Appears in Every Negotiation Document
The article by Winberg, Du, and Shi presents the first quantitative citation analysis of real-world evidence within the CMS MFP Explanation documents. Across 1,822 unique citations reviewed from these ten documents, 27.6% were classified as RWE. Usage varied substantially by drug, ranging from 13.8% for Farxiga to 41.5% for Xarelto.
Although RWE appeared in the citation lists for all ten drugs, the documents provided no information on how these studies were evaluated for quality or relevance. The MFP documents also did not disclose the extent to which RWE influenced the final negotiated prices. This lack of methodological transparency limits external assessment of the negotiation process.
Claims Data Dominates Evidence Base
The analysis reveals a clear preference for certain types of real-world data. Nearly half (47.0%) of the RWE citations relied on claims or administrative databases, followed by electronic health record (EHR) data and registry or clinical cohort data, each accounting for 17.1%. Survey or questionnaire data appeared in 8.2% of RWE studies, while systematic reviews or meta-analyses of real-world studies comprised 3.6%.
Cohort Studies Lead Methodological Choices
The overwhelming majority (82.1%) of RWE citations employed cohort or longitudinal designs. Cross-sectional or survey designs represented 11.0%, while systematic reviews or meta-analyses of real-world studies accounted for 3.6%. Three drugs—Eliquis, Xarelto, and Enbrel—also cited Institute for Clinical and Economic Review (ICER) assessments, while Farxiga referenced a National Institute for Health and Care Excellence (NICE) technology appraisal.
Study Offers Replicable Framework for Evidence Review
The researchers conducted a structured review of all references appearing in the publicly available MFP Explanation documents. Each citation was evaluated using an inclusive definition of RWE that encompassed studies using real-world data sources such as claims, EHR, registries, and surveys, as well as systematic reviews, meta-analyses, case-control studies, and certain descriptive analyses. This transparent, replicable approach provides a baseline characterization of documented RWE use while explicitly acknowledging that citation does not equate to demonstrated influence on negotiated prices.
Call for Stronger Documentation Standards
The observed variability in RWE citation rates across therapeutic areas, combined with the predominance of claims-based studies and the absence of any explanation of evidentiary weighting, highlights important opportunities to strengthen the Medicare negotiation framework.
For Health Economics and Outcomes Research (HEOR) professionals and manufacturers developing evidence strategies, these findings highlight the continued importance of generating high-quality RWE from diverse sources. Greater transparency regarding how CMS evaluates RWE quality, relevance, and relative contribution to price determinations in Medicare Drug Price Negotiations could enhance stakeholder confidence and align Medicare processes more closely with international standards.
