Assessing the Validity and Reliability of the Zwisch Scale in Plastic Surgery Residency.

Abstract

The Zwisch scale is a recognized model for assessing surgical skills competency and autonomy, with paucity of its application in plastic surgery field. We look to assess the validity of utilizing this model for plastic surgery residency programs. This 6-month pilot study was a prospective study with attending surgeons from 3 different teaching hospitals. Two samples were obtained. The first sample contained all procedures performed by a participating faculty member and resident during a specified time period. The second sample was a subset of the first consisting of 15 procedures. The procedures were observed in person by 2 additional surgeons who rated the resident's performance leveraging the Zwisch scores. A third surgeon utilized the operative skill assessment tool- Ottawa Surgical Competency OR Evaluation (O-SCORE) to provide ratings. All ratings were confidential. Six residents and 5 attendings participated with a total number of 126 encounters for 184 procedures. The association between the Q1 (complexity of procedure- easiest, average, hardest) and Q2 (Zwisch level) was estimated with Spearman's correlation and tested using Chi-square test. ICC and Spearman's rank correlation coefficient demonstrated validity of the Zwisch scores in plastic surgery procedures with good reliability amongst attending surgeons with resident self-rating decreased score reliability (ICC Without self-rating 0.817, with self-rating 0.752). Plastic surgery cases are often more complex and have longer operative times making it difficult to evaluate residents. This research substantiates developing a specifically modified Zwisch scoring system for plastic surgery.