Which Global Rating Scale? A Comparison of the ASSET, BAKSSS, and IGARS for the Assessment of Simulated Arthroscopic Skills

AuthorMiddleton RM, Baldwin MJ, Akhtar K, Alvand A, Rees JL.


With the move to competency-based models of surgical training, a number of assessment methods have been developed. Of these, global rating scales have emerged as popular tools, and several are specific to the assessment of arthroscopic skills. Our aim was to determine which one of a group of commonly used global rating scales demonstrated superiority in the assessment of simulated arthroscopic skills.


Sixty-three individuals of varying surgical experience performed a number of arthroscopic tasks on a virtual reality simulator (VirtaMed ArthroS). Performance was blindly assessed by two observers using three commonly used global rating scales used to assess simulated skills. Performance was also assessed by validated objective motion analysis.


All of the global rating scales demonstrated construct validity, with significant differences between each skill level and each arthroscopic task (p < 0.002, Mann-Whitney U test). Interrater reliability was excellent for each global rating scale. Correlations of global rating scale ratings with motion analysis were high and strong for each global rating scale when correlated with time taken (Spearman rho, -0.95 to -0.76; p < 0.001), and correlation with total path length was significant and moderately strong (Spearman rho, -0.94 to -0.64; p < 0.001).


No single global rating scale demonstrated superiority as an assessment tool.

Clinical relevance

For these commonly used arthroscopic global rating scales, none was particularly superior and any one score could therefore be used. Agreement on using a single score seems sensible, and it would seem unnecessary to develop further scales with the same domains for these purposes.