A framework for evidence directness
Claim Fidelity
Claim Fidelity asks whether cited research actually matches the words in a health claim. A large literature can coexist with poor claim fidelity.
Eight dimensions
What HRD compares
InterventionFinnish sauna ≠ infrared sauna
PopulationHeart-failure patients ≠ healthy adults
DoseDaily protocol ≠ occasional use
DurationAcute response ≠ durable benefit
ComparatorNo treatment ≠ active treatment
OutcomeSoreness ≠ muscle recovery
MeasurementBiomarker ≠ clinical outcome
SettingSupervised study ≠ home device
Ratings
High, moderate or low
High means the central intervention and outcome closely match. Moderate signals material differences or incomplete reporting. Low means the claim substantially extrapolates beyond what was studied. Fidelity does not grade study quality or effectiveness.
Example
Research depth and fidelity are separate
Traditional sauna may have a large cardiovascular literature while a claim about infrared-sauna longevity has low fidelity. The broader research volume does not repair the modality mismatch.