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Grades of Recommendation (GOR)
| A. Studies with consistent LOE 1a and/or 1b |
| B. Studies with consistent LOE 2a, 2b, 3a, or 3b; or extrapolations from studies with LOE 1a or 1b |
| C. Studies with LOE 4 or extrapolations from studies with LOE 2a, 2b, 3a, or 3b |
| D. Studies with LOE 5 or troubling inconsistent or inconclusive studies of any level |
LOE, Level of evidence.
Data from Oxford Center for Evidence-based Medicine Levels of Evidence 30
