Table 1 Grading of recommendations according to GRADE system

1A

Strong recommendation, high-quality evidence

Benefits clearly outweigh risks 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 risks and burdens or vice versa

RCTs with important limitations or exceptionally strong evidence from observational studies

Strong recommendation; can apply to most patients in most circumstances without reservation

1C

Strong recommendation, low or very low-quality evidence

Benefits clearly outweigh risks 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 burdens

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 burdens

RCTs with important limitations 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 or very low-quality evidence

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

Observational studies or case series

Very weak recommendation; other alternatives may be equally reasonable