| Criteria for level of evidence of selected literature |
| Level |
Content |
| 1 |
Research satisfying all of the following three criteria: |
| Criteria 1. Good reference standard |
| Criteria 2. Consecutive patients' study |
| Criteria 3. Blind interpretation |
| Systematic review of level 1 |
| Randomized controlled trial or cross-sectional cohort study that compares index test with comparators |
| 2 |
Research satisfying the following two criteria: |
| Criteria 1. Good reference standard |
| Criteria 2. Consecutive patient study or blind interpretation |
| Systematic review of level 2 |
| Observational studies that compare index test with comparators |
| 3 |
Without consistently applied reference standards |
| 4 |
Case-control study |
| Poor or non-independent reference standard |
| 5 |
Expert opinion |
| Definition of overall evidence level for each clinical scenario |
| Overall Evidence level |
Definition |
| High (I) |
Results are from appropriately designed experiments with low risk of bias |
| Moderate (II) |
Results are from appropriately designed experiments with intermediate risk of bias |
| Low (III) |
Results are from inappropriately designed experiments, or risk of bias is high |
| Very low (IV) |
Results are from inappropriately designed experiments, or risk of bias is high |
