An adequate level of training for technical competence in screening and diagnostic colonoscopy: a prospective multicenter evaluation of the learning curve

Background: Various training programs in colonoscopy recommend that trainees should perform at least 100 to 200 procedures to be considered technically competent at diagnostic colonoscopy. Objective: Our purpose was to determine the adequate level of training for technical competence in screening and diagnostic colonoscopy. Design: A prospective multicenter trial. Setting: Fifteen tertiary care academic medical centers. Patients: Over 8 months we prospectively evaluated the procedures of 24 first-year GI fellows in 15 tertiary care academic medical centers. A total of 4351 colonoscopies were assessed prospectively with variable clinical factors. Intervention: Cecal intubation was documented by photographing the identified cecal landmarks, including the appendiceal orifice and the ileocecal valve. Main Outcome Measurements: Acquisition of competence (success rate) was evaluated for colonoscopic training on the basis of 2 objective criteria: (1) adjusted completion rate (>90%) and (2) cecal intubation time (<20 minutes). Results: The overall success rate was 83.5% (3635/4351). The mean cecal intubation time was 9.23 ± 4.63 minutes. The success rate significantly improved and reached the requisite standard of competence after 150 procedures (71.5%, 82.6%, 91.3%, 94.4%, 98.4%, and 98.7%, respectively, for every 50 consecutive blocks). The polyp detection rate did not improve significantly during the 8 months and was not correlated with the learning curve. In addition, mean time to cecal intubation decreased significantly, from 11.16 to 8.39 minutes, after 150 procedures. Logistic regression analysis found that prolonged cecal intubation was caused by the following factors: elderly patients, female sex, low body mass index, poor bowel preparation, poor American Society of Anesthesiologists status, abdominal pain as an indication, instructor's supervision, and low case volume. Limitations: We did not record final pathologic reports of detected polyps and withdrawal time. Conclusions: Competence in technically efficient screening and diagnostic colonoscopy generally requires experience with more than 150 cases. Also, factors associated with prolonged cecal intubation for typical trainees did not differ from those for experienced colonoscopists.