The hierarchy level of evidence
The agency has introduced a hierarchy of evidence in order to enable a common understanding of the certainty of effects.
STAR has introduced a hierarchy of evidence in order to enable a common understanding of the certainty of effects. There are certain criteria to each level in the hierarchy:
- Strong: A majority of 3 or more effect studies of high quality and/or 1 researched literature review that shows results pointing in the same direction
- Moderate evidence: A majority of 2 effect studies of high quality that show results pointing in the same direction.
- Indication: A majority of 1 effect study of high quality or more studies with limited quality that show results pointing in the same direction.
- Conflicting knowledge: Effect studies that show results pointing in opposite directions.
- Uncertain knowledge: No or few effect studies of only limited quality. No majority of results.
“Evidence” means that there is a high certainty that the effects are true. “Indication” means that the level of certainty is lower and “no knowledge” means that the existing evidence either points in different directions or that there exists no or only limited research on the subject.