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

Abstract

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.

Emerging trends of inflammatory bowel disease in South Korea: A nationwide population‐based study

“…There may also be a truly increased incidence of IBD among younger individuals resulting from increasing urbanization and household changes in South Korea. Previous studies have shown that residing in an urban setting is associated with higher incidences of both CD and UC whereas residing in rural areas provides a protective effect that was prominent among younger (< 30 years) age groups . South Korea has experienced rapid urbanization, a significant increase in the number of young, urban singles, and a concomitant increase in the number of lone dwellers aged < 30 years .…”

“…Previous studies have shown that residing in an urban setting is associated with higher incidences of both CD and UC whereas residing in rural areas provides a protective effect that was prominent among younger (< 30 years) age groups. 25,26 South Korea has experienced rapid urbanization, a significant increase in the number of young, urban singles, and a concomitant increase in the number of lone dwellers aged < 30 years. 27 In addition, fresh food and vegetable consumption remains low, and dining out has grown substantially, especially among young singles (KOSIS, http://kosis.kr/).…”

Rural and Urban Differences in the Risk of Inflammatory Bowel Disease and Subsequent Health Services Utilization in Ontario

“…We highlight two recent multi-province studies conducted by the Canadian Gastro-Intestinal Epidemiology Consortium that evaluated rural-urban differences in the epidemiology of IBD (Benchimol et al 2017) and health services utilization and outcomes in patients with IBD (Benchimol et al 2018).…”

No association between urbanisation, neighbourhood deprivation and IBD: a population-based study of 4 million individuals

“…While neighbourhood deprivation has been linked to health and disease,5 data on IBD are scarce 6. In this nationwide study of more than 4 million Swedish residents, some 20 000 individuals developed IBD after the age of 10 years.…”