Colonoscopies done in doctors’ offices more likely to be incomplete

Ontarians who have a colonoscopy to detect colorectal cancer (CRC) performed in a doctor’s office or private clinic are three times more likely to have an incomplete procedure than patients who have a colonoscopy done in a hospital.

“Few reports have examined the completeness of colonoscopy in usual clinical practice using population-based studies. There is also little information concerning explanatory factors for incomplete colonoscopy,” said Dr. Linda Rabeneck, senior author of the study and an ICES senior scientist.

“This information is important because it could be used to identify circumstances most likely to lead to incomplete colonoscopy. Quality improvement programs could then be developed to increase completion rates in a targeted manner, and thus potentially decrease colorectal cancer miss rates.”

In their study, investigators identified men and women, 50 to 74 years of age, who underwent a first colonoscopy in Ontario between January 1999 and December 2003. Within this group, they evaluated the association between patient, endoscopist (specialty, colonoscopy volume), and setting factors (academic hospital, community hospital, doctor’s office) and incomplete colonoscopy.

Of the more than 331,000 individuals who had a first colonoscopy, 43,483 (13%) were incomplete. Patients with an incomplete colonoscopy were older, more likely to be female, or have a history of prior abdominal surgery or pelvic surgery. The results also showed that for colonoscopies done in a doctor’s office or private clinic, the odds of an incomplete procedure were more than three-fold greater than for procedures done in an academic hospital.

“There has been rapid growth of office-based colonoscopy in many Canadian cities because of constrained access to endoscopy resources in hospitals, particularly in academic health sciences centres. However, office-based endoscopy is unregulated; there are no standards for endoscope disinfection, credentialing of endoscopists, or monitoring after the use of sedation,” said Dr. Rabeneck.

“Therefore, a potential explanation for the higher rate of incomplete colonoscopies in offices is that the procedures are more likely to be performed with less or no sedation so more procedures may be abandoned because of patient discomfort. But we can only speculate at this time. We need further study to fully understand why having a procedure in an office or private clinic is associated with a higher rate of incomplete colonoscopy.”

Dr. Rabeneck also stresses that “endoscopists need to be particularly careful to ensure that patients who are older, female, or have a history of abdominal or pelvic surgery have complete procedures. And if a patient does not know the volume of procedures performed by their physician, then they should request a gastroenterologist, since gastroenterologists have the lowest percentage of incomplete colonoscopies across endoscopist specialties.”

The study, “Factors associated with incomplete colonoscopy: a population-based study”, is in the June 2007 issue of the journal Gastroenterology.

Author affiliations: ICES (Drs. Paszat, Stukel and Rabeneck, Mr. Saskin); Toronto Sunnybrook Regional Cancer Centre (Dr. Rabeneck); Departments of Medicine (Drs. Shah and Rabeneck), Radiation Oncology (Dr. Paszat), and Health Policy, Management and Evaluation (Drs. Paszat, Stukel and Rabeneck), University of Toronto.

ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy.

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