gms | German Medical Science

Kongress Medizin und Gesellschaft 2007

17. bis 21.09.2007, Augsburg

Validity of self-reported endoscopies of the large bowel and implications for estimates of colorectal cancer risk

Meeting Abstract

  • Michael Hoffmeister - Deutsches Krebsforschungszentrum, Heidelberg
  • Jenny Chang-Claude - Deutsches Krebsforschungsforschungszentrum, Heidelberg
  • Hermann Brenner - Deutsches Krebsforschungsforschungszentrum, Heidelberg

Kongress Medizin und Gesellschaft 2007. Augsburg, 17.-21.09.2007. Düsseldorf: German Medical Science GMS Publishing House; 2007. Doc07gmds563

The electronic version of this article is the complete one and can be found online at:

Published: September 6, 2007

© 2007 Hoffmeister et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Background: Large bowel endoscopy with removal of polyps strongly reduces colorectal cancer (CRC) risk. In epidemiological studies, ascertainment of large bowel endoscopies often relies on self-reports and might be prone to imperfect recall.

Methods: We assessed the validity of self-reported colorectal endoscopies in a population-based case-control study from Germany including 540 cases with histologically confirmed incident CRC and 614 control persons (DACHS study). We sought to obtain all medical records for the last self-reported endoscopy and for a subsample of 100 subjects reporting no previous endoscopy, and calculated odds ratios (ORs) of CRC risk according to self-reports and medical records.

Results: In total, 377 of 483 medical records for the last self-reported colorectal endoscopy could be obtained (78%). Sensitivity of self-reports was 100% and specificity ranged from 93-99% among subgroups defined by age, gender, education, family history of CRC, and case-control status. Adjusted OR (95% confidence interval) for CRC risk after previous colonoscopy was 0.31 (0.21-0.45) using self-reports and 0.31 (0.20-0.47) using medical records. However, agreement between self-reports and medical records was poor regarding type of endoscopy (colonoscopy, sigmoidoscopy or rectoscopy; kappa=0.22), moderate concerning polypectomy (kappa=0.58), and reasonable for year of examination (kappa=0.70).

Conclusions: Self-reports of previous colorectal endoscopies agreed well with medical records. However, validation appears to be essential with respect to details of the examination.