The GRADE (Grading of Recommendations Assessment, Development and Evaluation) system rates the quality of evidence from RCTs initially as 'High' which may be downgraded. Which factor can UPGRADE the quality of evidence from observational studies?
- A Large magnitude of effect (very strong association) with dose-response relationship ✓
- B Publication bias in the systematic review
- C Inconsistency of results across included studies
- D Indirect comparison of outcomes across different patient populations
Correct answer: A. Large magnitude of effect (very strong association) with dose-response relationship
Explanation
In GRADE, observational studies start as 'Low' quality evidence but can be upgraded when: (1) there is a large magnitude of effect (RR >2 or <0.5), (2) there is a dose-response gradient, or (3) all plausible confounders would attenuate or reverse the effect. Evidence is downgraded for risk of bias, inconsistency, indirectness, imprecision, and publication bias. Strong associations with dose-response in observational data can warrant upgrading.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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