Rising Incidence of Childhood Intussusception in Ontario: A Population-Based Study From 1997-2016.

BACKGROUND Intussusception is the most common cause of bowel obstruction in children aged 3 months to 6 years of age. We sought to describe patterns of incident childhood intussusception. METHODS A retrospective longitudinal cohort study utilizing population-based health administrative data and a validated case definition was used to identify patients <18 years of age treated for intussusception between January 1, 1997 and December 31, 2016 in Ontario, Canada. Descriptive statistics, graphical analyses, and a Poisson regression model were performed for trend analysis. RESULTS The overall incidence of intussusception in Ontario children (<18 years) was 3.3 cases/100,000 child years (cyrs), 95% CI [3.2.3.5]. The overall incidence increased from .9 cases/100,000 cyrs to 2.3 cases/100,000 cyrs. The highest incidence was in children aged 6-12 months at 28.9 cases/100,000 cyrs, 95% CI [26.2.31.9]. Incidence increased in all age-groups between 6 months and 5 years (at a rate of 5% to 16% per year; all P < .05). Month of year did not predict intussusception counts in a log-linear Poisson models, nor did rotavirus immunization implementation in 2011. There was a 3-fold variability across geographic areas in the province. There was a high rate of readmission for recurrence within 1 year (10.7%). CONCLUSION The incidence of intussusception more than doubled in Ontario from 1997 to 2016. The incidence increased for children aged between 6 months and 5 years at a rate of 5-16% per year, suggesting that an increased rate of idiopathic intussusception is responsible for the increase in the province.