Research Methodology
By Kaden Coziar, Founder & Managing Editor · The RX Index Research
The RX Index research team uses sources appropriate to each claim. This page documents our source hierarchy, analytical standards, and quality controls.
Source Hierarchy
We rank sources by authority. Higher tiers override lower tiers when data conflicts:
- Tier 1: FDA prescribing information & official labels
- Tier 2: Published clinical trial results (peer-reviewed)
- Tier 3: ClinicalTrials.gov registry data
- Tier 4: Official manufacturer pricing pages
- Tier 5: SEC filings & investor presentations
- Tier 6: Medical society guidelines (ADA, AHA, TOS)
Verification Pipeline
- Source selection: We use sources appropriate to each claim, including FDA labels, ClinicalTrials.gov, peer-reviewed publications, official pricing pages and company filings, and medical-society guidance. We include citations alongside publications where available.
- Cross-referencing: We compare claims with independent sources when available and appropriate. Some facts, such as listed prices or exact label wording, are best verified against the issuing source; not every claim has two independent sources.
- Ongoing Verification: Pricing and availability data re-verified on a monthly cycle.
Medicaid enrollment-reach estimates
Earlier versions reported enrollment-based Coverage Reach estimates and related state-change percentages. The underlying enrollment file and reproducible calculation are not available with this release, so those estimates are withdrawn as citable findings pending methodological review.
Corrections
Found an error? Email hello@therxindex.com. All corrections are documented in the changelog.
Related research
- GLP-1 Clinical Trial Demographics — Label-based extraction and participant-weighted calculations.
- GLP-1 Clinical Trial Exclusion Criteria — Protocol-level source verification.
- GLP-1 Medicaid Coverage by State — State-by-state coverage research.