Table. Evidence levels and recommendation grades in the S3 guideline on the local treatment of chronic wounds.

Type of study	Quality levelaccording to GRADE (34)	Recommendation gradeand illustrative example
Systematic reviews (meta-analysis) and randomized controlled therapeutic trials	High (It is highly unlikely that further research will alter confidence in the observed treatment effect.)	Recommendation grade A Example: “Treatment X clearly should / should not be used”
Randomized controlled trials with an intermediate risk of systematic error	Moderate (Further research is likely to have a major impact on our confidence in the observed treatment effect. The treatment effect may turn out to be different than observed in this trial.)	Recommendation grade B Example: “Treatment X should / should not be used”
Randomized, controlled trials with a high risk of systematic error	Low (Further research will very likely have a major impact on our confidence in the observed treatment effect. The treatment effect will probably be different than observed in this trial.)	Recommendation grade O Example: “Treatment X can be used”