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Table 2 Class of recommendations

From: Role of cardiovascular magnetic resonance in the guidelines of the European Society of Cardiology

Class of recommendation


Suggested wording to use

Class I

Evidence and/or general agreement that a given treatment or procedure is beneficial, useful, effective.

Is recommended/is indicated

Class II

Conflicting evidence and/or a divergence of opinion about the usefulness/efficacy of the given treatment or procedure.


Class IIa

Weight of evidence/opinion is in favour of usefulness/efficacy.

Should be considered

Class IIb

Usefulness/efficacy is less well established by evidence/opinion.

May be considered

Class III

Evidence or general agreement that the given treatment or procedure is not useful/effective, and in some cases may be harmful.

Is not recommended