Reduction in surgical stoma rates in Crohn's disease: a population-based time trend analysis

Aim Trends in surgical rates for Crohn's disease (CD) in the biological era are controversial. We aim to assess modern trends in the formation rates of surgical stomas. Method Population-based surveillance in the Calgary Health Zone (CHZ), Canada, was conducted between 1 April 2002 and 31 March 2011, using the Discharge Database to identify adult patients with CD admitted to hospital and treated with surgical stoma formation (n = 545). Annual stoma incidence was calculated by dividing the number of incident stomas by the prevalence of CD in the CHZ. Time trend analysis of the stoma-formation rate was performed, expressed as annual percentage change (APC) with 95% CI. Stoma-formation rates were stratified according to procedure (emergency vs elective) and duration of stoma [temporary (reversed within 2 years of formation) vs permanent]. Results The overall rate of stoma formation between 2002 and 2011 showed a downwards trend, of a mean of 5.2% (95% CI: -8.5 to -1.8) per year, from a rate of 2.30 stomas/100 person-years (PY) in 2002 to 1.51 stomas/100 PY in 2011. The rate of emergency stoma formation decreased significantly from 2002 to 2011 (mean APC = -9.4%; 95% CI: -15.6 to -2.8), while the rate of elective ostomies essentially showed no change (mean APC = -0.9%; 95% CI: -5.3 to 3.8). The rate of temporary stoma formation decreased significantly, by 4.6% (95% CI: -7.3 to -1.8) per year, while permanent stoma formation was stable (APC = 1.0%; 95% CI: -4.0 to +6.3). Conclusion A reduction in the overall rate of stoma formation in CD has been driven by fewer emergency stomas, although rates of permanent stoma have remained stable.