Table 1 Grade of recommendation and underlying levels of evidence (SIGN and OCEBM); following the SIGN and the OCEBM grading system the levels of evidence are rated in four or five categories. Results of studies can be extrapolated or interpolated so that lower levels of evidence can underlie higher grades of recommendations and conversely
From: Evaluation of evidence grades in psychiatry and psychotherapy guidelines
Grade of recommendation | Description | Level of evidence (SIGN) | Level of evidence (OCEBM) |
|---|---|---|---|
A | Strong recommendation | 1++, 1+, (1-) | I, (II) |
B | Recommendation | 2++, 2+, (2-) | II, III, (I) |
or downgrading of 1++ / 1+ / (1-) due to methodological considerations | |||
0 | Open recommendation | 3,4 | IV, V, (II, III) |
or downgrading of 2++ / 2+ / (2-) due to methodological considerations | |||
CCP | Clinical consensus (different strengths of recommendation possible) | No level of evidence | No level of evidence |