Core GRADE 5: rating certainty of evidence-assessing indirectness.

Area of Science:

• Health research methodology
• Evidence-based practice

Background:

• Systematic reviews, clinical guidelines, and health technology assessments rely on robust evidence evaluation.
• The Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework is a key tool in this process.
• Addressing indirect evidence is crucial for accurate assessment.

Purpose of the Study:

• To present the Core GRADE approach for evaluating evidence, particularly indirect evidence.
• To guide guideline developers and health technology assessment practitioners in assessing evidence certainty.

Main Methods:

• Specifying the target Population, Intervention, Comparison, and Outcome (PICO).
• Comparing the target PICO with the PICO of available studies.
• Judging the likelihood of substantial differences in effect magnitude when study PICO differs from target PICO.

Main Results:

• When target and study PICOs differ significantly, studies provide indirect evidence.
• Indirectness can lead to a rating down of the certainty of evidence.
• The likelihood of substantial differences in effect magnitude influences the decision to rate down evidence certainty.

Conclusions:

• The Core GRADE approach provides a structured method for handling indirect evidence.
• Careful PICO specification and comparison are essential for accurate evidence assessment.
• Judicious rating down for indirectness enhances the reliability of recommendations and assessments.