General proxies for expertise in RCTs
| Expertise | Rationale |
|---|---|
| Proxies for learning curve | |
| Total no. of cases | To reach learning curve plateau |
| Annual case volume | Volume necessary to maintain proficiency |
| Yrs of independent practice | Prior experience with other type of surgeries could shorten the learning curve |
| Previous training | Affects the slope of learning curve |
| Competence | |
| Supervision before participation (e.g., Fellowship, extra training) | Indirect indication of competence |
| Performance/outcome assessment (e.g., audit) | Indication that competence and the learning plateau match the study’s predefined expertise levels |
| Recommendation by expert | Indirect indication of competence |
RCT = randomized controlled trial.