Crohn disease was not associated with increased risk for mortality
Hovde Ø, Kempski-Monstad I, Småstuen MC, et al. Mortality and causes of death in Crohn’s disease: results from 20 years of follow-up in the IBSEN study. Gut. 2013 Jun 6. [Epub ahead of print]
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Is Crohn disease associated with increased risk for mortality?
Patients with Crohn disease have episodes of acute inflammation of the intestine, and a wealth of data suggests that they have a prothrombotic state during a disease flare. Recurrent intestinal inflammation may lead to increased cell turnover and increased risk for gastrointestinal cancer, while the prothombotic state may increase risk for cardiovascular disease and pulmonary embolus. A meta-analysis of 9 population-based studies shows increased mortality in patients with compared with those without Crohn disease (standardized mortality ratio 1.4, 95% CI 1.3 to 1.5) (1). Risk for some cancers was increased, but risk for colorectal cancer was not. The excess death rate was related to complications of Crohn disease itself. Most of these studies reported data collected well before the biologic era, and newer data are needed.
Methods Design: Inception cohort followed for 20 years in the Inflammatory Bowel South-Eastern Norway (IBSEN) study. Mortality data were obtained from the Norwegian Causes of Death Register. Setting: Southeastern Norway. Patients: 237 patients (age range 7 to 84 y, median age 28 y at diagnosis, 50% boys and men) who had Crohn disease diagnosed by standardized criteria. 5876 age- and sex-matched persons who did not have Crohn disease comprised the control group. Prognostic factors: Crohn disease, age, and sex. Outcomes: All-cause and cause-specific mortality.
Main results Crohn disease was not associated with increased risk for all-cause or cause-specific mortality (Table).
Conclusion Crohn disease was not associated with increased risk for mortality. Source of funding: Innlandet Hospital, Norway. For correspondence: Dr. Ø. Hovde, Innlandet Hospital Trust, Gjøvik, Norway. E-mail [email protected]
■ Risk for mortality associated with Crohn disease at 20 y Outcomes
Incidence Crohn disease
Hazard ratio (95% CI)
No Crohn disease 13%
1.4 (0.9 to 1.9)*
Gastrointestinal cancer mortality
Nongastrointestinal cancer mortality
2.0 (1.0 to 4.5)*
Mortality due to other causes
The study by Hovde and colleagues is interesting given that the inception of the cohort was from 1991 to 1993, and its 20-year follow-up spanned the introduction of biologic therapy. Other strengths of the study are that the cohort was population-based, and few participants were lost to follow-up. The main concern is the small sample size, which limits precision. That the mean age of Crohn disease patients was only 28 years at inception of the cohort compounds the study’s lack of power to assess mortality. The point estimate of increased mortality (hazard ratio 1.4, CI 0.9 to 1.9) is similar to the systematic review findings, but the confidence intervals are wide, reflecting the modest event rate. With only 3 deaths from gastrointestinal cancer, this specific outcome cannot be adequately assessed. Overall, the study by Hovde and colleagues adds to our knowledge of risk for mortality in Crohn disease, but we need more data from the modern era to reach firm conclusions. Paul Moayyedi, MD Farncombe Family Digestive Health Research Institute Hamilton, Ontario, Canada Reference 1. Duricova D, Pedersen N, Elkjaer M, Gamborg M, Munkholm P, Jess T. Overall and cause-specific mortality in Crohn’s disease: a meta-analysis of population-based studies. Inflamm Bowel Dis. 2010;16:347-53.
*P value is not significant.
© 2013 American College of Physicians
19 November 2013 | ACP Journal Club | Volume 159 • Number 10
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