The learning curve in diagnosing acute appendicitis with emergency sonography among novice emergency medicine residents

PURPOSE: Ultrasonography (US) has good accuracy for diagnosing appendicitis when it is performed by emergency physicians. This study aimed to determine the amount of experience that is required to achieve competency in this field. METHODS: Three novice emergency medicine residents completed a 1-day training course regarding the US diagnosis of appendicitis. Then, they performed appendix US in the emergency department on patients complaining of right lower quadrant pain. All included patients also underwent computed tomography or US performed by a board-certified radiologist, to confirm the emergency US diagnosis. The agreement between the diagnoses of novices and experts was evaluated. RESULTS: A total of 266 patients were included, and the overall Cohen's kappa coefficient was 0.77 (95% confidence interval [CI]: 0.69-0.84). The kappa value of first 20 cases was 0.49 (95% CI: 0.27-0.71). It increased rapidly during evaluation of the first 20 cases. After the first 20 cases, the kappa coefficient was 0.84 (95% CI: 0.77-0.92). The sensitivity and specificity values for the first 20 cases were 64.3% (95% CI: 77.6%-90.7%) and 84.4% (95% CI: 85.4%-95.4%), respectively. After the first 20 cases, the sensitivity and specificity values increased to 90.9% (95% CI: 83.4%-95.8%) and 93.5% (95% CI: 87.0%-97.3%), respectively. CONCLUSIONS: A minimum of 20 cases are needed to achieve competency in emergency US diagnosis of acute appendicitis.