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- Published
- Updated
Early procedures with a new device may reflect operator experience as much as device characteristics. Rather than removing initial cases after seeing favourable results elsewhere, decide before study conduct how learning will be recorded, assessed and explained.
Define the assessment
Record previous procedural experience, device training and the order of procedures within the investigation separately. Attendance at training and demonstrated ability to perform independently answer different questions. Justify the proposed learning assessment for the device, procedure and intended setting instead of borrowing an arbitrary number of cases.
Worked example
In a hypothetical catheter investigation, the first five procedures take longer. The team examines supervision, additional manoeuvres and case complexity rather than automatically excluding those procedures. It considers whether experience explains the difference and reviews safety events separately from the procedural success measure.
Practical checks
- Record an auditable procedure sequence for each individual operator, not just each site.
- Reconcile training, supervised practice and independent procedure dates before interpreting experience.
- Explain how initial cases enter the analysis with the statistician before results are examined.
Decision and limitations
The assessment should let a reader understand experience alongside the principal result. Even when a run-in exclusion was planned, preserve safety follow-up and explain the excluded participants. No single number of learning cases is suitable for every device or operator population.
Frequently asked questions
- Must initial procedures be excluded?
- No. The scientific objective, design and prespecified analysis govern that decision. Poor performance alone does not justify retrospective exclusion.
- Does a training certificate establish proficiency?
- It may demonstrate attendance. Practical competence, supervision requirements and the distribution of experience need their own assessment.