TABLE 1.

Adapted grading system for recommendations

Classification Description
Class of evidence
Class 1	Strong recommendation
	There is high-quality evidence that supports the usefulness or efficacy of a given diagnostic test or treatment
Class 2	On the balance of evidence and opinion, there is support in favour of the usefulness or efficacy of a given diagnostic test or treatment
Class 2a	Weight of evidence/opinion is in favour of usefulness/efficacy
Class 2b	Usefulness/efficacy is less well established by evidence/opinion
Class 3	Cannot be recommended
	Conditions for which there is evidence and/or general agreement that a diagnostic evaluation, procedure or treatment is not useful or effective and in some cases may be harmful
Grade of evidence
Level A	High-quality evidence from multiple randomized clinical trials or meta-analyses
Level B	Data from a single randomized trial, or nonrandomized studies
	Further information might have an impact on our confidence of the practice
Level C	Consensus opinion of experts, or case studies
	Further information is needed to support the practice