Table 2 Rules for grading the recommendations

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