The GRADE Approach to Rating the Evidence

Appendix: 4.0 The GRADE Approach to Rating the Evidence

Table 10. Rating the Evidence for Benefit or Harm Using the GRADE Approach⁹

Type of Evidence: Starting GRADE

• RCT: High
• Observational study: Low

Criteria to Decrease GRADE

• Study quality limitations
  Serious (−1 GRADE) or very serious (−2 GRADE) study quality limitations determined by Risk of Bias Assessments
• Inconsistency
  Important inconsistency (−1 GRADE)
• Indirectness
  Some (−1 GRADE) or major (−2 GRADE) uncertainty about directness
• Imprecision
  Imprecise or sparse data (−1 GRADE)
• Publication bias
  High risk of bias (−1 GRADE)

Criteria to Increase GRADE

• Strength of association
  Strong (+1 GRADE) or very strong evidence of association (+2 GRADE)
• Dose-response
  Evidence of a dose-response gradient (+1 GRADE)
• Confounding
  Inclusion of unmeasured confounders increases the magnitude of effect (+1 GRADE)

Resulting GRADE

• High
• Moderate
• Low
• Very Low

Reference

9. Umscheid CA, Agarwal RK, Brennan PJ, Healthcare Infection Control Practices Advisory C. Updating the guideline development methodology of the Healthcare Infection Control Practices Advisory Committee (HICPAC). Am J Infect Control. 2010;38(4):264-273.