Rural and Urban Residence During Early Life is Associated with Risk of Inflammatory Bowel Disease: A Population-Based Inception and Birth Cohort Study

OBJECTIVES: To determine the association between inflammatory bowel disease (IBD) and rural/urban household at the time of diagnosis, or within the first 5 years (y) of life. METHODS: Population-based cohorts of residents of four Canadian provinces were created using health administrative data. Rural/urban status was derived from postal codes based on population density and distance to metropolitan areas. Validated algorithms identified all incident IBD cases from administrative data (Alberta: 1999-2008, Manitoba and Ontario: 1999-2010, and Nova Scotia: 2000-2008). We determined sex-standardized incidence (per 100,000 patient-years) and incident rate ratios (IRR) using Poisson regression. A birth cohort was created of children in whom full administrative data were available from birth (Alberta 1996-2010, Manitoba 1988-2010, and Ontario 1991-2010). IRR was calculated for residents who lived continuously in rural/urban households during each of the first 5 years of life. RESULTS: There were 6,662 rural residents and 38,905 urban residents with IBD. Incidence of IBD per 100,000 was 33.16 (95% CI 27.24-39.08) in urban residents, and 30.72 (95% CI 23.81-37.64) in rural residents (IRR 0.90, 95% CI 0.81-0.99). The protective association was strongest in children <10 years (IRR 0.58, 95% CI 0.43-0.73) and 10-17.9 years (IRR 0.72, 95% CI 0.64-0.81). In the birth cohort, comprising 331 rural and 2,302 urban residents, rurality in the first 1-5 years of life was associated with lower risk of IBD (IRR 0.75-0.78). CONCLUSIONS: People living in rural households had lower risk of developing IBD. This association is strongest in young children and adolescents, and in children exposed to the rural environment early in life.

Corrigendum: Rural and Urban Residence During Early Life Is Associated with a Lower Risk of Inflammatory Bowel Disease: A Population-Based Inception and Birth Cohort Study.

This corrects the article DOI: 10.1038/ajg.2017.208.

Rural and urban disparities in the care of Canadian patients with inflammatory bowel disease: a population-based study.

BACKGROUND AND AIMS: Canada's large geographic area and low population density pose challenges in access to specialized health care for remote and rural residents. We compared health services use, surgical rate, and specialist gastroenterologist care in rural and urban inflammatory bowel disease (IBD) patients in Canada. METHODS: We used validated algorithms that were applied to population-based health administrative data to identify all people living with the following three Canadian provinces: Alberta, Manitoba, and Ontario (ON). We compared rural residents with urban residents for time to diagnosis, hospitalizations, outpatient visits, emergency department (ED) use, surgical rate, and gastroenterologist care. Multivariable regression compared the outcomes in rural/urban patients, controlling for confounders. Provincial results were meta-analyzed using random-effects models to produce overall estimates. RESULTS: A total of 36,656 urban and 5,223 rural residents with incident IBD were included. Outpatient physician visit rate was similar in rural and urban patients. IBD-specific and IBD-related hospitalization rates were higher in rural patients (incidence rate ratio [IRR] 1.17, 95% CI 1.02-1.34, and IRR 1.27, 95% CI 1.04-1.56, respectively). The rate of ED visits in ON were similarly elevated for rural patients (IRR 1.53, 95% CI 1.42-1.65, and IRR 1.33, 95% CI 1.25-1.40). There were no differences in surgical rates or prediagnosis lag time between rural and urban patients. Rural patients had fewer IBD-specific gastroenterologist visits (IRR 0.79, 95% CI 0.73-0.84) and a smaller proportion of their IBD-specific care was provided by gastroenterologists (28.3% vs 55.2%, P<0.0001). This was less pronounced in children <10 years at diagnosis (59.3% vs 65.0%, P<0.0001), and the gap was widest in patients >65 years (33.0% vs 59.2%, P<0.0001). CONCLUSION: There were lower rates of gastroenterologist physician visits, more hospitalizations, and greater rates of ED visits in rural IBD patients. These disparities in health services use result in costlier care for rural patients. Innovative methods of delivering gastroenterology care to rural IBD patients (such as telehealth, online support, and remote clinics) should be explored, especially for communities lacking easy access to gastroenterologists.