TABLE 1.

Strength of recommendations and quality of evidence

Strength	Definition
A	Strong recommendation
	Should always be offered
	Experts agree
B	Moderate recommendation
	Should usually be offered
	Most experts agree
C	Optional recommendation
	May be offered
	Expert opinion varies
Grade	Definition
I	Evidence from at least one proper randomized, controlled trial
II	Evidence from at least one well-designed clinical trial without randomization from cohort or case-controlled analytical studies, or from dramatic results of uncontrolled experiments
III	Evidence from opinions of respected authorities based on clinical experience, descriptive studies or reports of expert committees

Data from reference 9