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INTRODUCTION Environmental factors related to urbanization and industrialization are believed to be involved in inflammatory bowel disease (IBD) development, but no study has looked at the association between greenspace and IBD. METHODS We conducted a retrospective cohort study using linked population-based health administrative and environmental data sets. The study population comprised 2,715,318 mother-infant pairs from hospital births in Ontario, Canada, between April 1, 1991, and March 31, 2014. We measured the exposure to residential greenspace using the normalized difference vegetation index derived using remote-sensing methods. Average greenspace was estimated for the pregnancy and childhood periods. We used mixed-effects Cox proportional hazard models to assess potential associations between residential greenspace and the risk of developing IBD before 18 years while adjusting for covariates including sex, maternal IBD, rural/urban residence at birth, and neighborhood income. RESULTS There were 3,444 IBD diagnoses that occurred during follow-up. An increase in the interquartile range of residential greenspace during the childhood period was associated with a lower risk of developing pediatric-onset IBD (hazard ratio [HR] 0.77, 95% confidence interval [CI] 0.74-0.81). This relationship was significant for both ulcerative colitis (HR 0.72 95% CI 0.67-0.78) and Crohn's disease (HR 0.81, 95% CI 0.76-0.87). There was a linear dose response across increasing quartiles of greenspace (P < 0.0001). No consistent association was detected between maternal intrapartum greenspace exposure and pediatric-onset IBD. DISCUSSION Higher exposure to residential greenspace during childhood was associated with a reduced risk of IBD, suggesting a novel avenue to prevent IBD in children.

OBJECTIVES The prevalence of inflammatory bowel disease (IBD) is increasing. The total direct costs of IBD have not been assessed on a population-wide level in the era of biologic therapy. DESIGN We identified all persons with IBD in Manitoba between 2005 and 2015, with each matched to 10 controls on age, sex, and area of residence. We enumerated all hospitalizations, outpatient visits and prescription medications including biologics, and their associated direct costs. Total and per capita annual IBD-attributable costs and health care utilization (HCU) were determined by taking the difference between the costs/HCU accrued by an IBD case and their controls. Generalized linear modeling was used to evaluate trends in direct costs and Poisson regression for trends in HCU. RESULTS The number of people with IBD in Manitoba increased from 6,323 to 7,603 between 2005 and 2015. The total per capita annual costs attributable to IBD rose from $3,354 in 2005 to $7,801 in 2015, primarily driven by an increase in per capita annual anti-tumor necrosis factor costs, which rose from $181 in 2005 to $5,270 in 2015. There was a significant decline in inpatient costs for CD ($99 ± 25/yr. P < 0.0001), but not for ulcerative colitis ($8 increase ±$18/yr, P = 0.63). DISCUSSION The direct health care costs attributable to IBD have more than doubled over the 10 years between 2005 and 2015, driven mostly by increasing expenditures on biological medications. IBD-attributable hospitalization costs have declined modestly over time for persons with CD, although no change was seen for patients with ulcerative colitis.

Inflammatory Bowel Disease in Immigrants to Canada And Their Children: A Population-Based Cohort Study

Objectives: Temporal changes for intestinal resections for Crohn’s disease (CD) are controversial. We validated administrative database codes for CD diagnosis and surgery in hospitalized patients and then evaluated temporal trends in CD surgical resection rates. Methods: First, we validated International Classification of Disease (ICD)-10-CM coding for CD diagnosis in hospitalized patients and Canadian Classification of Health Intervention coding for surgical resections. Second, we used these validated codes to conduct population-based surveillance between fiscal years 2002 and 2010 to identify adult CD patients undergoing intestinal resection (n=981). Annual surgical rate was calculated by dividing incident surgeries by estimated CD prevalence. Time trend analysis was performed and annual percent change (APC) with 95% confidence intervals (CI) in surgical resection rates were calculated using a generalized linear model assuming a Poisson distribution. Results: In the validation cohort, 101/104 (97.1%) patients undergoing surgery and 191/200 (95.5%) patients admitted without surgery were confirmed to have CD on chart review. Among the 116 administrative database codes for surgical resection, 97.4% were confirmed intestinal resections on chart review. From 2002 to 2010, the overall CD surgical resection rate was 3.8 resections per 100 person-years. During the study period, rate of surgery decreased by 3.5% per year (95% CI: −1.1%, −5.8%), driven by decreasing emergent operations (−10.1% per year (95% CI: −13.4%, −6.7%)) whereas elective surgeries increased by 3.7% per year (95% CI: 0.1%, 7.3%). Conclusions: Overall surgical resection rates in CD are decreasing, but a paradigm shift has occurred whereby elective operations are now more commonly performed than emergent surgeries.