Definition of the level of evidence
| Sign | Level of evidence | Definition |
|---|---|---|
| I | High | • Research design: • (Intervention) These are the results obtained from randomized controlled trials or comparative group observational studies. • (Diagnosis) These are the results obtained from randomized controlled trials or diagnostic accuracy studies in the form of cross-sectional cohorts. • Considerations: There are no methodological concerns in the quality assessment of the evidence, and the evidence is consistent and precise, ensuring high reliability of the synthesized results. |
| II | Moderate | • Research design: • (Intervention) These are the results obtained from randomized controlled trials or comparative group observational studies. • (Diagnosis) These are the results obtained from randomized controlled trials or cross-sectional cohort diagnostic accuracy studies. • There are slight concerns regarding the quality assessment of the evidence, the consistency of the evidence, or the precision of the evidence, resulting in a moderate level of confidence in the synthesized results. |
| III | Low | • Research design: • (Intervention) These are the results obtained from observational studies with or without a control group. • (Diagnosis) These are the results obtained from diagnostic accuracy studies with a patient-control group design. |
| IV | Very low | • Research design: • (Intervention) These are composed of observational studies without a control group or expert opinions, reviews, and the like. • (Diagnosis) These are the results obtained from diagnostic accuracy studies with a patient-control group design. • Considerations: There are very serious concerns regarding the quality assessment of the evidence, the consistency of the evidence, or the precision of the evidence, resulting in very low confidence in the synthesized results. |