| Recommendation ratings |
| A |
Good evidence for efficacy and substantial clinical benefit support recommendation for use. |
| B |
Moderate evidence for efficacy or only limited clinical benefit supports recommendation for use. |
| C |
Evidence for efficacy is insufficient to support a recommendation for or against use, but recommendations may be made on other grounds. |
| D |
Moderate evidence for lack of efficacy or for adverse outcome supports a recommendation against use. |
| E |
Good evidence for lack of efficacy or for adverse outcome supports a recommendation against use. |
| Quality of evidence |
| I |
Evidence from at least one randomized, controlled trial. |
| II |
Evidence from at least one clinical trial without randomization, from cohort or case-controlled analytic studies (preferably from more than one center) or from multiple time-series studies or dramatic results from uncontrolled experiments. |
| III |
Evidence from opinions of respected authorities based on clinical experience, descriptive studies, or reports of expert committees. |
