Table 1.

Type of grading and definition of grades

Grading type	Definition
Strength of the recommendation (SOR)
Grade 1	Strong recommendation (for or against)
	Applies to most patients in most circumstances
	Benefits clearly outweigh the risk (or vice versa)
Grade 2	Weak recommendation (for or against)
	Best action may differ depending on circumstances or patient values
	Benefits and risks or burdens are closely balanced, or uncertain
Quality of the evidence (QOE)
+++	High quality; evidence at low risk of bias, such as randomized trials showing consistent results directly applicable to the recommendation
++	Moderate quality; studies with methodological flaws, showing inconsistent or indirect evidence
+	Low quality; case series or unsystematic clinical observations

The SOR is indicated by the number 1 or 2. Grade 1 indicates a strong recommendation (for or against), while grade 2 indicates a weak recommendation or a suggestion that may not be appropriate for every patient, depending on context, patient values and preferences. Grading the quality of the evidence took into account study design, study quality, consistency of results and directness of the evidence. The QOE is indicated by plus signs at three levels. Each recommendation is preceded by a description of the evidence.