Table 1 Grading of recommendations after [7]

1A

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

1B

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

1C

Strong recommendation, low-quality 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

2A

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

2B

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

2C

Weak recommendation, Low-quality or very low-quality evidence

Uncertainty in the estimates of benefits, risks and burden; benefits, risk and burden may be closely balanced

Observational studies or case series

Very weak recommendation; other alternatives may be equally reasonable