Table 2 Rules for grading the recommendations
Strength of recommendation and quality of evidence Benefit vs. risk and burdens Methodological quality of supporting evidencea Implications
Strong recommendation, high-quality evidence Benefits clearly outweigh risk and burdens, or vice versa RCTs without important limitations or overwhelming evidence from observational studies Strong recommendation, can apply to most patients in most circumstances without reservation
Strong recommendation, moderate quality evidence Benefits clearly outweigh risk and burdens, or vice versa RCTs with important limitations (inconsistent results, methodological flaws, indirect or imprecise) or exceptionally strong evidence from observational studies Strong recommendation, can apply to most patients in most circumstances without reservation
Strong recommendation, low or very low quality evidence Benefits clearly outweigh risk and burdens, or vice versa Observational studies or case series Strong recommendation but may change when higher quality evidence becomes available
Weak recommendation, high-quality evidence Benefits closely balanced with risks and burden RCTs without important limitations or overwhelming evidence from observational studies Weak recommendation, best action may differ depending on circumstances or patients’ or societal values
Weak recommendation, moderate quality evidence Benefits closely balanced with risks and burden RCTs with important limitations (inconsistent results, methodological flaws, indirect or imprecise) or exceptionally strong evidence from observational studies Weak recommendation, best action may differ depending on circumstances or patients’ or societal values
Weak recommendation, low or very low quality evidence Uncertainty in the estimates of benefits, risks and burden; benefits, risk and burden may be in a closely balanced Observational studies or case series Very weak recommendations; other alternatives may be equally reasonable
RCTs randomized controlled trials
aThe evidence agreed on by more than 70% frontline clinicians in consensus meeting is viewed as high-quality evidence