TABLE A2. Recommendation Rating Definitions

Term	Definitions
Quality of Evidence
High	We are very confident that the true effect lies close to that of the estimate of the effect.
Moderate	We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different.
Low	Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect.
Very low	We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect.
Strength of Recommendation
Strong	In recommendations for an intervention, the desirable effects of an intervention outweigh its undesirable effects.
	In recommendations against an intervention, the undesirable effects of an intervention outweigh its desirable effects.
	All or almost all informed people would make the recommended choice for or against an intervention.
Weak	In recommendations for an intervention, the desirable effects probably outweigh the undesirable effects, but appreciable uncertainty exists.
	In recommendations against an intervention, the undesirable effects probably outweigh the desirable effects, but appreciable uncertainty exists.
	Most informed people would choose the recommended course of action, but a substantial number would not.