Original CommunicationsAppendectomy and subsequent risk of inflammatory bowel diseases*,**
Section snippets
Methods
Since 1977, a nationwide registration system has recorded more than 99% of all hospitalizations in Denmark.23 For each hospitalization, the register contains the 10-digit personal identifier (incorporating codes for sex and date of birth) unique to each citizen in Denmark, date of discharge, surgical procedures, and medical discharge diagnoses. Procedures are coded according to a national classification system,24 and diagnoses are coded according to a Danish version of the International
Results
Our cohort of 154,434 appendectomy patients (40% men, 60% women) included 10% who had the operation because of perforating appendicitis and 49% who had other appendiceal disease (Table I).Empty Cell Men Women Total Person-years* Average follow-up (y) Empty Cell No. % No. % No. % Empty Cell Empty Cell Year of appendectomy 1977-1980 19,903 32% 31,173 34% 51,076 33% 536,795 10.5 1981-1984 19,568 31% 29,331 32% 48,899 32% 329,935 6.7 1985-1989
Discussion
This cohort study fails to support the previously reported association between appendectomy and risk of ulcerative colitis. We had considerable power to detect as statistically significant risk reductions of between 36% and 98% as reported in previous studies.4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 Indeed, our overall estimate of the RR (RR = 0.87; 95% CI, 0.69-1.07) excludes a reduction in the risk of ulcerative colitis after appendectomy of more than 31% and, being close
Conclusion
This study, the first based on prospective data from a large population-based cohort study, does not support a relationship between appendectomy and ulcerative colitis in the first decade after appendectomy. The association with Crohn's disease most likely reflects differential diagnostic problems in patients with abdominal pain. Additional cohort studies with longer follow-up are warranted, as are case-control studies of incident cases of ulcerative colitis and population controls using
Addendum
Since submission, 2 additional case-control studies and 1 follow-up study have been published.44, 45, 46 Both case-control studies had methodological problems as seen in prior studies, including unmatched analysis of matched data,44 use of different methods for ascertaining appendectomies in cases and controls,45 and failure to specify the ascertainment period for appendectomies among controls.44, 45 A follow-up study in Sweden46 compared incident hospitalization rates for ulcerative colitis
Acknowledgements
We thank Andrea Bautz for skillful computer assistance and Drs Charles S. Rabkin, Michie Hisada, and Henrik Hjalgrim for fruitful discussions of the study subject.
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Association between prior appendectomy and the risk and course of Crohn's disease: A systematic review and meta-analysis
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2023, Clinical Gastroenterology and HepatologyThe immunological functions of the Appendix: An example of redundancy?
2018, Seminars in ImmunologyCitation Excerpt :Appendectomy is often performed in CD patients, before their diagnosis. This may lead to the subsequent diagnosis of CD being considered to be associated with appendectomy, but in reality this relationship appears as a bias rather than a true association [100,105,111]. Animal models will be required to unravel the role of the Appendix in the development of IBD.
Second European evidence-based Consensus on the diagnosis and management of ulcerative colitis Part 1: Definitions and diagnosis
2014, Revista de Gastroenterologia de MexicoAppendectomy and Crohn's Disease
2019, Journal of ColoproctologyCitation Excerpt :However, with regard to CD, the information about this association is still not very consistent. Some studies have shown a positive association between appendectomy and CD development.11,17–22 Other studies failed to prove any association,23 and there are even studies that have shown a negative association,4 as in UC.
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Supported by research grant MAO NO1-CP-85639-04 from the National Cancer Institute, Bethesda, MD, and by grants from Direktør E. Danielsen og Hustrus Foundation, The Foundation for the Advancement of Medical Science, Grosserer L. F. Foghts Foundation, Lily Benthine Lunds Foundation, and the Danish Medical Research Council.
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Reprint requests: Dr Morten Frisch, Department of Epidemiology Research, Danish Epidemiology Science Center, Statens Serum Institut, 5 Artillerivej, DK-2300 Copenhagen, Denmark.