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Gut doi:10.1136/gut.2007.121467

The risk of developing Crohn's disease after an appendectomy: A population-based cohort study in Sweden and Denmark

  1. Gilaad G Kaplan (ggkaplan{at}ucalgary.ca)
  1. Massachusetts General Hospital Crohn's and Colitis Center & Harvard University, United States
    1. Bo V Pedersen (bvp{at}ssi.dk)
    1. Statens Serum Institut, Denmark
      1. Roland E Andersson (roland.andersson{at}lj.se)
      1. University Hospital, Linköping, Sweden
        1. Bruce E Sands (bsands{at}partners.org)
        1. Massachusetts General Hospital Crohn's and Colitis Center & Harvard University, United States
          1. Joshua Korzenik (jkorzenik{at}partners.org)
          1. Massachusetts General Hospital Crohn's and Colitis Center & Harvard University, United States
            1. Morten Frisch (mfr{at}ssi.dk)
            1. Statens Serum Institut, Denmark
              • Published Online First 9 May 2007

              Abstract

              Background: The relationship between appendectomy and Crohn's disease (CD) is controversial. We conducted a Swedish-Danish cohort study to assess the risk of developing CD after an appendectomy.

              Methods: 709,353 appendectomy patients in Sweden (since 1964) and Denmark (since 1977) were followed for first hospitalizations for CD through 2004. Standardized incidence ratios (SIRs) served as relative risks.

              Results: Overall, 1655 CD cases were observed during 11.1 million person-years of follow-up. While appendectomy before age 10 was not associated with CD risk (SIR = 1.00; 95% confidence interval (CI): 0.80 - 1.25), the overall SIR of developing CD was 1.52 (95% CI: 1.45 - 1.59), being highest in the first 6 months (SIR = 8.69; 95% CI: 7.68 - 9.84). SIRs diminished rapidly thereafter, with CD risk reaching background levels after 5-10 years for CD overall, as well as for Crohn's ileitis, ileocolonic CD, Crohn's colitis and other/unspecified CD. Long-term increased CD risk up to 20 years after the appendectomy was seen only in appendectomy patients without appendicitis or mesenteric lymphadenitis.

              Conclusion: The transient increased risk of Crohn's disease following an appendectomy is likely explained by a diagnostic bias.

              This Article

              1. Abstract
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              3. All versions of this article:
                1. gut.2007.121467v1
                2. gut.2007.121467v2
                3. 56/10/1387most recent

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