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Canadian Journal of Gastroenterology and Hepatology
Volume 2017 (2017), Article ID 5917057, 11 pages
Research Article

Repeat Colonoscopy within 6 Months after Initial Outpatient Colonoscopy in Ontario: A Population-Based Cross-Sectional Study

1Institute for Clinical Evaluative Sciences, University of Toronto, G106 2075 Bayview Avenue, Toronto, ON, Canada M4N 3M5
2Department of Surgery and Li Ka Shing Knowledge Institute, St. Michael’s Hospital, University of Toronto, 30 Bond Street, Toronto, ON, Canada M5B 1W8
3Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview Avenue, Toronto, ON, Canada M4N 3M5
4Prevention and Cancer Control, Cancer Care Ontario, University of Toronto, 620 University Avenue, Toronto, ON, Canada M5G 2L7

Correspondence should be addressed to Lawrence Paszat;

Received 29 May 2017; Revised 1 August 2017; Accepted 17 August 2017; Published 7 September 2017

Academic Editor: Salvatore Cucchiara

Copyright © 2017 Lawrence Paszat et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Background. The goal of this study is to examine utilization of early repeat colonoscopy ≤ 6 months after an index procedure. Methods. We identified persons having repeat colonoscopy ≤ 6 months following outpatient colonoscopy without prior colonoscopy ≤ 5 years or prior diagnosis of colorectal cancer (CRC). We modeled repeat colonoscopy using a generalized estimating equation with an exchangeable correlation structure to account for clustering of patients by endoscopist. Results. The population included 334,663 persons, 7,892 (2.36%) of whom had an early repeat colonoscopy within 6 months. Overall, endoscopist prior year colonoscopy volume was inversely related to repeat ≤ 6 months. Repeat colonoscopy ≤ 6 months varied by the clinical setting of the index colonoscopy (adjusted OR = 1.41 (95% CI 1.29–1.55)) at nonhospital facilities compared to teaching or community hospitals. Among those who had polypectomy or biopsy, the adjusted OR for early repeat ≤ 6 months was elevated among those whose index colonoscopy was at a nonhospital facility (OR 1.44, 95% CI 1.30–1.60), compared to those at a teaching hospital or community hospital. Conclusions. Repeat colonoscopy ≤ 6 months after an index procedure is associated with the clinical setting of the index colonoscopy.