Empiric Evidence for Revision of Minimum Index Case Numbers for Accreditation of Plastic Surgery Training

Training programs for surgical specialties are often required to provide a minimum operative experience for their trainees. Such minimum case numbers are meant to ensure adequate clinical resources exist for trainees to reach some level of proficiency by completion of training. Failure of a program to provide the minimum required experience is a common accreditation citation and can carry significant consequences. Yet minimum required numbers often are based on little to no evidence that if a trainee achieves that degree of experience there is some guarantee he will be competent with that procedure. In plastic surgery, minimum required numbers are currently based on the tenth percentile of all programs’ clinical volume determined nearly 20 years ago. The goal of this study was to provide empirical evidence for revised minimum numbers by surveying chief residents and recent graduates (trainees) and teaching faculty. An ideal minimum required number was operationally defined as that after which 90% of trainees would be able to perform a typical example of such a case independently without a complication rate above the norm. The craniofacial subset of plastic surgery cases was used for this study. Trainees were asked whether they were comfortable with these cases, and how many cases were required to achieve that comfort. Faculty were asked how many cases would be required before they would grant independence for trainees with these cases. Quality of non-operative education related to craniofacial cases was treated as a potential confounder. The performance of the suggested numbers was evaluated by applying them back to trainees’ actual case log data. Comfort with craniofacial cases under the current numbers was low. There was remarkable agreement between trainees and faculty regarding the number of cases required. The minimum numbers suggested were higher than current minima, and performed well as thresholds for determining when 90% of trainees would report comfort with these cases. Quality of non-operative education was not a significant factor. Comfort with cases was felt due mostly to specific experience with those cases, but overall surgical training was almost equally important. This study provided empirical evidence for revised minimum numbers for accreditation of plastic surgery training. There was good validity evidence for the numbers proposed, suggesting that this method may be an efficient way of acquiring similar data in other areas of plastic surgery in the future. An advantage of this method over some other more specific measures of surgical skill is that it may automatically account for the context in which learning occurs.