Mid-day Nadir in Adenoma Detection Rates Suggests That Scheduled Endoscopistsʼ Breaks Can Optimize Colorectal Cancer Screening

Abstract

Introduction: Adenoma detection rate (ADR) is an accepted indicator of colonoscopy quality. To the best of our knowledge, hourly variation in ADR has not been evaluated in screening colonoscopies performed in full day blocks. This study aims to examine this relationship. Methods: A retrospective review of electronic records of all screening colonoscopies performed at an urban university medical center hospital over a 12-month period was conducted. Only screening colonoscopies with the first procedure beginning in the morning were included. Procedures from half day blocks beginning in the afternoon were excluded. Procedures for indications other than average risk colon cancer screening were also excluded. Patient age, gender and race were recorded. Microsoft Excel was used to generate a database that maintained patient confidentiality. Statistical analysis was performed using Fisher Exact test, with significance set at p < 0.05. The study was approved by the university institutional review board. Results: 887 colonoscopy records (508 women, 379 men) were reviewed. Eight faculty gastroenterologists performed all colonoscopies. There were 267 Caucasian patients, 471 African-American patients, 56 Hispanic patients, and 93 patients of other or undocumented ethnicity. The mean patient age was 58.6 years (+/- 8.44). Adenomas were detected in 409 patients (ADR 46.15%). The average withdrawal time was 13.55 minutes (+/- 6.44 minutes). The average start times of the first and last procedure of the day were 8:56 am (+/- 35 minutes) and 3:53 PM (+/- 50 minutes) respectively. ADR for the earliest (n=90) and latest procedures (n=33) of the day were 43.3% and 42.2% (p= 1.0) respectively. ADR reached a nadir at 12 PM (n=111, ADR 31.1%), which was significantly decreased from 11 am (n=102, ADR 50%, P = 0.005) and 12:30 PM (n=81, ADR 46.91%, p=0.035). ADR peaked at 2:25 PM (n=70, ADR 70%). Conclusion: There is significant (38.9%) variation in ADR (p==0.0001) for screening colonoscopies performed over a full day, with the nadir ADR observed around noon. Possible explanations include relief of endoscopy staff at lunch by non-endoscopy operating room staff, potentially impacting on procedure quality. Alternatively, endoscopists may hasten procedures in effort to incorporate an unplanned break into their schedules. Attention to procedure scheduling to ensure optimal examinations is important. Further study of ADR variation based upon procedure timing is necessary.