Learning Curve Cumulative Summation Method for Ocular Ultrasound

The current American College of Emergency Physicians (ACEP) guidelines recommend that trainees perform 25 ocular ultrasound scans before being considered competent. This threshold has not been substantiated for ocular ultrasound. The purpose of this study was to determine the number of ocular scans required to reach competency in ocular ultrasound using the learning curve cumulative sum (LC-CUSUM) analysis. A secondary objective was to evaluate whether individualized learning curve feedback influences competency attainment.

Using the LC-CUSUM method with an 85% success threshold, we assessed the number of scans needed to achieve competency in both image acquisition and interpretation among first-year emergency medicine residents. For a secondary analysis, residents were then randomized into two groups: one receiving bimonthly personalized learning curve updates alongside standard feedback, and another receiving standard feedback alone. Competency attainment was compared between groups.

Twenty-six residents were included. LC-CUSUM analysis determined that 21 studies were needed to reach competency. The median number of scans per resident was 26.5 (IQR: 22-30). At the end of the academic year, 17 residents (65%) reached technical competency, 10 residents (35%) reached interpretation competency, and 10 residents (35%) reached competency in both domains. Fifteen residents (58%) remained in the learning phase. There was no significant difference between competency attainment or perceived feedback in the randomized feedback groups.

LC-CUSUM analysis suggests that competency in ocular ultrasound may be achieved after approximately 21 individual-eye scans, or approximately 10.5 bilateral ocular exams, fewer than half the 25 bilateral examinations recommended by ACEP. Individualized learning curve feedback did not improve competency attainment or perceptions of feedback compared with standard feedback.