Table 1.

Grading of evidence and recommendation according to the GRADE system [1]

Evidence quality	Notes	Grading
High	Further research is very unlikely to change our confidence in the estimation of effect	A
Moderate	Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate	B
Low	Further research is very unlikely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Any change of estimate is uncertain	C
Recommendation	Notes	Grading
Strong	Factors influencing the strength of the recommendation included the quality of the evidence, presumed patient-important outcomes, and cost	1
Weak	Variability in the preferences and values, or more uncertainty. Recommendation is made with less certainty, higher cost or resource consumption	2