Open-access colonoscopy in Ontario: Associated factors and quality

BACKGROUND: Open-access (OA) colonoscopy may increase efficiency and decrease wait times; however, because the patient is seen for the first time at the endoscopy appointment, previous processes, such as information about the procedure, preparation and appropriate triage, may be suboptimal. OBJECTIVE: To identify factors associated with OA colonoscopy and to determine the relationship between OA colonoscopy and an important quality measure, incomplete colonoscopy. METHODS: A population-based analysis of all adult outpatients undergoing a first-time colonoscopy between 1997 and 2007 in Ontario was performed. Colonoscopy was considered to be OA if there were no visits in the preceding five years with the physician performing the colonoscopy. Using logistic regression, patient, physician and institution factors associated with OA colonoscopy were identified. Using propensity score matching, the relationship between OA colonoscopy and incomplete colonoscopy in 2006 was examined. RESULTS: A total of 1,079,259 colonoscopies were performed. Of these, 14% were OA in 1997 compared with 26% in 2007. Patients 50 to 69 years of age, those from higher-income neighbourhoods and those with less comorbidity were more likely to undergo OA colonoscopy. The odds of receiving OA colonoscopy were six times greater in a nonhospital clinic compared with a community hospital. Colonoscopy was more likely to be complete if the procedure was OA (OR 1.3 [ 95% CI 1.2 to 1.4]; P<0.0001). CONCLUSIONS: Rates of OA colonoscopy have increased substantially since 1997. Institution type was most strongly associated with OA colonoscopy. Colonoscopy completeness, a recognized quality indicator, does not appear to be compromised by OA colonoscopy.