Exploratory analysis on the usage of Pi-score algorithm over endoscopic stone treatment step 1 protocol.

Background: The Performance Improvement score (Pi-score) has been proven to be reliable to measure performance improvement during E-BLUS hands-on training sessions. Our study is aimed to adapt and test the score to EST s1 (Endoscopic Stone Treatment step 1) protocol, in consideration of its worldwide adoption for practical training.

Methods: The Pi-score algorithm considers time measurement and number of errors from two different repetitions (first and fifth) of the same training task and compares them to the relative task goals, to produce an objective score. Data were obtained from the first edition of 'ART in Flexible Course', during four courses in Barcelona and Milan. Collected data were independently analyzed by the experts for Pi assessment. Their scores were compared for inter-rater reliability. The average scores from all tutors were then compared to the PI-score provided by our algorithm for each participant, in order to verify their statistical correlation. Kappa statistics were used for comparison analysis.

Results: Sixteen hands-on training expert tutors and 47 3-year residents in Urology were involved. Concordance found between the 16 proctors' scores was the following: Task 1=0.30 ("fair"); Task 2=0.18 ("slight"); Task 3=0.10 ("slight"); Task 4=0.20, ("slight"). Concordance between Pi-score results and proctor average scores per-participant was the following: Task 1=0.74 ("substantial"); Task 2=0.71 ("substantial"); Task 3=0.46 ("moderate"); Task 4=0.49 ("moderate").

Conclusions: Our exploratory study demonstrates that Pi-score can be effectively adapted to EST s1. Our algorithm successfully provided an objective score that equals the average performance improvement scores assigned by of a cohort of experts, in relation to a small amount of training attempts.