Low rate of large polyps (>9 mm) within 10 years after an adequate baseline colonoscopy with no polyps.
OBJECTIVE
Guidelines recommend a 10-year interval between screening colonoscopies with negative results for average-risk individuals. However, many patients are examined at shorter intervals. We investigated outcomes of individuals with no polyps who had repeat colonoscopy in <10 years.


METHODS
Data were collected using the National Endoscopic Database, from 69 gastroenterology centers, on 264,184 asymptomatic subjects who underwent screening colonoscopies from 2000 through 2006, were found to have no polyps, and received another colonoscopy examination within <10 years.


RESULTS
No polyps were found in 147,375 patients during a baseline colonoscopy; 17,525 patients (11.9%) had a follow-up colonoscopy within <10 years, including 1806 (10.3%) who received the follow-up colonoscopy within <1 year. The most common reason for repeating the examination within 1 year was that the first was compromised by inadequate bowel preparation or incomplete examination. Of these patients, 6.5% (95% confidence interval: 5.3-7.6) had large polyp(s) >9 mm-a proportion similar to the prevalence in the average-risk screening population. Reasons that examinations were repeated within 1-5 years included average-risk screening (15.7%), family history of colon polyps or cancer (30.1%), bleeding (31.2%), gastrointestinal symptoms (11.8%), or a positive result from a fecal blood test (5.5%). If the baseline examination was adequate, the incidence of large polyps within 1-5 years after baseline colonoscopy was 3.1% (95% confidence interval: 2.7-3.5) and within years 5-10 years was 3.7% (95% confidence interval: 3.3-4.1).


CONCLUSIONS
Repeat colonoscopies within 10 years are of little benefit to patients who had adequate examinations and were found to have no polyps. Repeat colonoscopies are beneficial to patients when the baseline examination was compromised.
Division of Gastroenterology, Oregon Health and Science University, Portland, Oregon. Electronic address: lieberma@ohsu.edu.
David A
DA
Lieberman
Division of Gastroenterology, Oregon Health and Science University, Portland, Oregon.
Jennifer L
JL
Holub
Department of Medical Informatics and Clinical Epidemiology, Oregon Health and Science University, Portland, Oregon.
Cynthia D
CD
Morris
Department of Medical Informatics and Clinical Epidemiology, Oregon Health and Science University, Portland, Oregon.
Judith
J
Logan
Division of Gastroenterology, Oregon Health and Science University, Portland, Oregon.
J Lucas
JL
Williams
Department of Family Medicine, Oregon Health and Science University, Portland, Oregon.
Patricia
P
Carney
D003106:Colon / Q000473:pathology*; D003110:Colonic Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology; D003111:Colonic Polyps / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology; D003113:Colonoscopy; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011237:Predictive Value of Tests; D015995:Prevalence; D012307:Risk Factors; D013997:Time Factors; D047368:Tumor Burden; D014481:United States / Q000453:epidemiology; D019564:Unnecessary Procedures
Colorectal; Early Detection; Neoplasm; Prevention