Charles J. Kahi, MD, MSc *; Heiko Pohl, MD *; Laura J. Myers, PhD; Dalia Mobarek, MD, MSc; Douglas J. Robertson, MD; Thomas F. Imperiale, MD
Financial Support: By a VA Clinical Science Research & Development Grant (1 I01 CX000589-01A2) to Drs. Kahi and Pohl. Support for VA–CMS data is provided by the Department of Veterans Affairs, Veterans Health Administration, Office of Research and Development, Health Services Research and Development, VA Information Resource Center (project numbers SDR 02-237 and 98-004). This work was also supported using resources and facilities at the VA Informatics and Computing Infrastructure, VA HSR RES 13-457.
Disclosures: Dr. Robertson reports personal fees from Medtronic outside the submitted work. Authors not named here have disclosed no conflicts of interest. Disclosures can also be viewed at www.acponline.org/authors/icmje/ConflictOfInterestForms.do?msNum=M17-0723.
Editors' Disclosures: Christine Laine, MD, MPH, Editor in Chief, reports that her spouse has stock options/holdings with Targeted Diagnostics and Therapeutics. Darren B. Taichman, MD, PhD, Executive Editor, reports that he has no financial relationships or interests to disclose. Cynthia D. Mulrow, MD, MSc, Senior Deputy Editor, reports that she has no relationships or interests to disclose. Deborah Cotton, MD, MPH, Deputy Editor, reports that she has no financial relationships or interest to disclose. Jaya K. Rao, MD, MHS, Deputy Editor, reports that she has stock holdings/options in Eli Lilly and Pfizer. Sankey V. Williams, MD, Deputy Editor, reports that he has no financial relationships or interests to disclose. Catharine B. Stack, PhD, MS, Deputy Editor for Statistics, reports that she has stock holdings in Pfizer and Johnson & Johnson.
Reproducible Research Statement:Study protocol and statistical code: Available from Dr. Kahi (e-mail, firstname.lastname@example.org). Data set: The authors are unable to provide access to the data because of data use agreements that prohibit disclosing data (identifiable or deidentified) outside the VHA.
Requests for Single Reprints: Charles J. Kahi, MD, MS, Professor of Clinical Medicine, Indiana University School of Medicine, Gastroenterology Section Chief, Roudebush VA Medical Center, 1481 West 10th Street, 111G, Indianapolis, IN 46202; e-mail, email@example.com.
Current Author Addresses: Dr. Kahi: Professor of Clinical Medicine, Indiana University School of Medicine, Gastroenterology Section Chief, Roudebush VA Medical Center, 1481 West 10th Street, 111G, Indianapolis, IN 46202.
Dr. Pohl: Department of Hepatology and Gastroenterology, White River Junction VA Medical Center, 215 North Main Street, White River Junction, VT 05009.
Dr. Myers: HSR&D Center of Excellence, Roudebush VA Medical Center, 1481 West 10th Street, Indianapolis, IN 46202.
Dr. Mobarek: Veterans Affairs Medical Center, 50 Irving Street, NW, Suite 2C North 128, Washington, DC 20422.
Dr. Robertson: Division of Gastroenterology, Department of Medicine (111E), White River Junction VA Medical Center, 215 North Main Street, White River Junction, VT 05009.
Dr. Imperiale: Regenstrief Institute, Inc., Indiana University, 1101 West 10th Street, Indianapolis, IN 46202.
Author Contributions: Conception and design: C.J. Kahi, H. Pohl, D.J. Robertson, T.F. Imperiale.
Analysis and interpretation of the data: C.J. Kahi, H. Pohl, L.J. Myers, D.J. Robertson.
Drafting of the article: C.J. Kahi, H. Pohl, L.J. Myers, D. Mobarek, T.F. Imperiale.
Critical revision of the article for important intellectual content: C.J. Kahi, H. Pohl, L.J. Myers, D. Mobarek, D.J. Robertson, T.F. Imperiale.
Final approval of the article: C.J. Kahi, H. Pohl, L.J. Myers, D. Mobarek, D.J. Robertson, T.F. Imperiale.
Statistical expertise: L.J. Myers.
Obtaining of funding: C.J. Kahi, H. Pohl.
Administrative, technical, or logistic support: C.J. Kahi.
Collection and assembly of data: H. Pohl, L.J. Myers, D. Mobarek.
Colonoscopy is widely used in the Veterans Affairs (VA) health care system for colorectal cancer (CRC) prevention, but its effect on CRC mortality is unknown.
To determine whether colonoscopy is associated with decreased CRC mortality in veterans and whether its effect differs by anatomical location of CRC.
VA–Medicare administrative data.
Case patients were veterans aged 52 years or older who were diagnosed with CRC between 2002 and 2008 and died of the disease by the end of 2010. Case patients were matched to 4 control patients without prior CRC on the basis of age, sex, and facility. Conditional logistic regression was performed to calculate odds ratios (ORs) for exposure to colonoscopy, with adjustment for race, Charlson Comorbidity Index score, selected chronic conditions, nonsteroidal anti-inflammatory drug use, and family history of CRC.
Exposure to colonoscopy was determined from 1997 to 6 months before CRC diagnosis in case patients and to a corresponding date in control patients. Subgroup analysis was performed for patients who had undergone screening colonoscopy.
A total of 4964 case patients and 19 856 control patients were identified. Case patients were significantly less likely to have undergone any colonoscopy (OR, 0.39 [95% CI, 0.35 to 0.43]). Colonoscopy was associated with reduced mortality for left-sided cancer (OR, 0.28 [CI, 0.24 to 0.32]) and right-sided cancer (OR, 0.54 [CI, 0.47 to 0.63]). The results were similar for patients who had undergone screening colonoscopy (overall OR, 0.30 [CI, 0.24 to 0.38]). Sensitivity analyses that varied the interval between CRC diagnosis and colonoscopy exposure did not affect the primary findings.
In this study using national VA–Medicare data, colonoscopy was associated with significant reductions in CRC mortality among veterans and was associated with greater benefit for left-sided cancer than right-sided cancer.
U.S. Department of Veterans Affairs.
Kahi CJ, Pohl H, Myers LJ, Mobarek D, Robertson DJ, Imperiale TF. Colonoscopy and Colorectal Cancer Mortality in the Veterans Affairs Health Care System: A Case–Control Study. Ann Intern Med. 2018;168:481–488. doi: 10.7326/M17-0723
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Published: Ann Intern Med. 2018;168(7):481-488.
Published at www.annals.org on 6 March 2018
Colonoscopy/Sigmoidoscopy, Colorectal Cancer, Gastroenterology/Hepatology, Gastrointestinal Cancer, Hematology/Oncology.
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