Quantitative and individualized assessment of the learning curve using LC-CUSUM

Current methods available for assessing the learning curve, such as a predefined number of procedures or direct observation by a tutor, are unsatisfactory. A new tool, the cumulative summation test for learning curve (LC-CUSUM), has been developed that allows quantitative and individual assessment of the learning curve.

Some 532 endoscopic retrograde cholangiopancreatographies (ERCPs) performed by one endoscopist over 8 years were analysed retrospectively using LC-CUSUM to assess the learning curve. The procedure was new to the endoscopist and monitored prospectively in the initial study. Success of the procedure was defined as cannulation and proper visualization of the duct(s) selected before the examination.

Fifty ERCPs were considered unsuccessful. There was a gradual improvement in performance over time from a success rate of 82.0 per cent for the first 100 procedures to 96.1 per cent for the last 129 procedures. The LC-CUSUM signalled at the 79th procedure, indicating that sufficient evidence had accumulated to prove that the endoscopist was competent.

LC-CUSUM allows quantitative monitoring of individual performance during the learning process.