Complications of Colonoscopy in an Integrated Health Care Delivery System

19 December 2006 | Volume 145 Issue 12 | Pages 880-886

Background: Information about colonoscopy complications, particularly postpolypectomy bleeding, is limited.

Objective: To quantify the magnitude and severity of colonoscopy complications.

Design: Retrospective cohort.

Setting: Kaiser Permanente of Northern California.

Patients: 16 318 members 40 years of age or older undergoing colonoscopy between January 1994 and July 2002.

Measurements: Electronic records reviewed for serious complications, including hospital admission within 30 days of colonoscopy for colonic perforation, colonic bleeding, diverticulitis, the postpolypectomy syndrome, or other serious illnesses directly related to colonoscopy.

Results: 82 serious complications occurred (5.0 per 1000 colonoscopies [95% CI, 4.0 to 6.2 per 1000 colonoscopies]). Serious complications occurred in 0.8 per 1000 colonoscopies without biopsy or polypectomy and in 7.0 per 1000 colonoscopies with biopsy or polypectomy. Perforations occurred in 0.9 per 1000 colonoscopies (CI, 0.5 to 1.5 per 1000 colonoscopies) (0.6 per 1000 without biopsy or polypectomy and 1.1 per 1000 with biopsy or polypectomy). Postbiopsy or postpolypectomy bleeding occurred in 4.8 per 1000 colonoscopies with biopsy (CI, 3.6 to 6.2 per 1000 colonoscopies). Biopsy or polypectomy was associated with an increased risk for any serious complication (rate ratio, 9.2 [CI, 2.9 to 29.0] vs. colonoscopy without biopsy). Ten deaths (1 attributable to colonoscopy) occurred within 30 days of the colonoscopy.

Limitations: 99.3% (16 204) of colonoscopies were nonscreening examinations. The rate of complications may be lower in a primary screening sample. The small number of observed adverse events limited power to detect risk factors for complications.

Conclusions: Colonoscopy with biopsy or polypectomy is associated with increased risk for complications. Perforation may also occur during colonoscopies without biopsies.

Editors' Notes Context Data on the frequency of colonoscopy complications from population-based samples are lacking. Contribution The authors searched electronic health records at Kaiser-Permanente of Northern California for patients who died or who had complications due to colonoscopy within 30 days of the procedure. Almost all procedures were diagnostic or for surveillance of previous abnormal findings. Of 16 318 eligible procedures, 82 involved serious complications (5 in 1000 procedures). Of the 82 complications, 95% followed biopsy or removal of polyps, and 62% of the polyps removed were smaller than 10 mm. The perforation rate was 1 in 1000 procedures. One death was related to colonoscopy. Cautions Less than 1% of procedures studied were screening colonoscopies, so these complication rates might not apply to screening examinations. —The Editors

 

Author and Article Information

From Kaiser Permanente Medical Care Program, Oakland, California; Battelle Memorial Institute, Seattle, Washington; and the Centers for Disease Control and Prevention, Atlanta, Georgia.

Disclaimer: The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention.

Acknowledgments: The authors thank Patricia Leighton for providing able project management, Alice Moore for performing medical records analysis, and Jocelyne Miller, MD, for collaborating in the adjudication of causes of hospitalizations.

Grant Support: Centers for Disease Control and Prevention (contract number GS-23F-8167H; task order number MC2-06).

Potential Financial Conflicts of Interest: None disclosed.

Request for Single Reprints: Theodore R. Levin, MD, Kaiser Permanente, 2000 Broadway, Oakland, CA 94612; e-mail, Theodore.Levin{at}kp.org.

Current Author Addresses: Drs. Levin and Conell and Ms. Zhao: Kaiser Permanente, 2000 Broadway, Oakland, CA 94612.

Drs. Manninen and Schulman: Battelle Memorial Institute, 1100 Dexter Avenue North, Seattle, WA 98109.

Dr. Schulman: Battelle Memorial Institute, Crystal City, VA.

Drs. Seeff and Shapiro: Centers for Disease Control and Prevention, MS K-55, Atlanta, GA 30341.

Author Contributions: Conception and design: T.R. Levin, L.C. Seeff, J.A. Shapiro, D.L. Manninen.

Analysis and interpretation of the data: T.R. Levin, W. Zhao, C. Conell, L.C. Seeff, J.A. Shapiro, D.L. Manninen.

Drafting of the article: T.R. Levin, C. Conell, L.C. Seeff, D.L. Manninen.

Critical revision of the article for important intellectual content: T.R. Levin, W. Zhao, L.C. Seeff, J.A. Shapiro, J. Schulman.

Final approval of the article: T.R. Levin, W. Zhao, L.C. Seeff, J.A. Shapiro.

Statistical expertise: C. Conell, J. Schulman.

Obtaining of funding: T.R. Levin, L.C. Seeff, J.A. Shapiro.

Collection and assembly of data: W. Zhao, C. Conell.

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