Introduction: Global rating scales (GRSs) such as the Objective Structured Assessment of Technical Skills (OSATS) and Global Operative Assessment of Laparoscopic Surgery (GOALS) are assessment methods for surgical procedures. The aim of this study was to establish construct validity of Procedure-Based Assessment (PBA) and to compare PBA with GRSs for laparoscopic cholecystectomy.
Material and methods: OSATS and GOALS GRSs were compared with PBA in their ability to discriminate between levels of performance between trainees who can perform the procedure independently and those who cannot. Three groups were formed based on the number of procedures performed by the trainee: novice (1-10), intermediate (11-20) and experienced (>20). Differences between groups were assessed using the Kruskal-Wallis and Mann-Whitney U tests.
Results: Increasing experience correlated significantly with higher GRSs and PBA scores (all p < .001). Scores of novice and intermediate groups overlapped substantially on the OSATS (p = .1) and GOALS (p = .1), while the PBA discriminated between these groups (p = .03). The median score in the experienced group was higher with less dispersion for PBA (97.2[85.3-100]) compared to OSATS (82.1[60.7-100]) and GOALS (80[60-100]).
Conclusion: For assessing skill level or the capability of performing a laparoscopic cholecystectomy independently, PBA has a higher discriminative ability compared to the GRSs.
Keywords: Laparoscopic cholecystectomy; construct validity; key steps; procedure-based assessment (PBA); summative assessment.