Table 2. Grading of recommendations.

Grade classification	Explanation
Strong for	The benefit of intervention is greater than the harm with a high or moderate level of evidence that can be strongly recommended in most clinical practices.
Weak for	The benefit and harm of the intervention may vary depending on the clinical situation or patient/social value. It is recommended conditionally according to the clinical situation.
Weak against	The benefit and harm of intervention may vary depending on the clinical situation or patient/social value. The intervention may not be recommended in clinical practice.
Strong against	The harm of intervention is greater than the benefit with a high or moderate level of evidence. The intervention should not be recommended in clinical practice.
No recommendation	It is impossible to determine the recommended direction owing to a lack of evidence or discrepancy in results. Thus, further evidence is needed.