Process quality and incidence of acute complications in a series of more than 230 000 outpatient colonoscopies

Background and study aims: Data on process quality and complications of colonoscopies are sparse, especially for the screening setting. We describe process quality in routine care, estimate the incidence of acute complications, and identify risk indicators for substandard care and complications. Patients and methods: We analyzed data from 236 087 compulsory health insurance (CHI) members who underwent colonoscopies in 2006. Data were documented prospectively in the Electronic Colonoscopy Documentation of the Bavarian Association of CHI Physicians, a registry of outpatient colonoscopies performed in practices throughout Bavaria, Germany. It covers demographic characteristics, indications, quality indicators, macroscopic and histological findings, diagnoses, and acute complications. Results: Colon preparation resulted in clear bowels in 76.31% of patients, liquid residues in 22.22%, and dirty bowels in 1.47%. In total, 92.85% of the examinations were performed with patients under sedation/analgesia and 97.43% of colonoscopies were complete. Photodocumentation was present for 98.87%. Male sex, middle age, screening, satisfactory bowel preparation, and sedation/analgesia were associated with completeness. A total of 735 patients (0.31%) suffered complications, among them 520 bleedings (0.22%), 69 perforations (0.03%), and 152 cardiorespiratory complications (0.06%). Male sex, higher age, nonscreening indication, biopsies, polypectomies, and absence of sedation/analgesia were indicative of a higher bleeding risk. Perforations were also related to biopsies and polypectomies. Higher age was the only discernible risk indicator for cardiorespiratory events. Conclusions: Outpatient colonoscopy is a safe procedure with a low risk of acute complications. Improving bowel preparation enhances completeness. Sedation/analgesia is conducive to both completeness and the lowering of the risk of acute complications.