Table 1.

GRADE Framework consisting of four grades of quality of evidence and two grades of strength of recommendation

GRADE Framework
A. Quality of evidence
High quality	Well performed randomized control trials or clear evidence from multiple well-conducted observational studies showing very large effect
Moderate quality	Randomized control trials with essential limitations
Low quality	Observational studies or controlled trial with severe limitations
Very low quality	Non-systematic observations, biologic reasoning, or observational studies with severe limitations
B. Strength of recommendation
Strong	A strong recommendation was given when benefits distinctly outweighed the risks for nearly all patients. As practitioners, most patients must receive this course of action
Weak	A weak recommendation was given when risks and benefits were more closely balanced or were uncertain. As practitioners, patients must be explained about all the different options, and an option suitable for patient needs must be chosen