Geographic inequalities of respiratory health services utilization during childhood in Edmonton and Calgary: a tale of two cities

Introduction. Young children are susceptible to respiratory diseases. Inequalities exist across socioeconomic groups (SES) for a variety of pediatric respiratory diseases in Alberta. However, the geographic distribution of inequalities in respiratory health services utilization in early childhood has not been fully explored. The main aim of this study was to identify geographic inequalities in respiratory health services utilization in early childhood in Calgary and Edmonton.
Methods. We conducted a cross-sectional geographic analysis of data from a retrospective cohort of all singleton live births that occurred in Calgary and Edmonton between 2005 and 2010. We extracted individual data on hospitalizations and emergency department (ED) visits between birth and five years of age associated with a primary diagnosis of acute bronchiolitis, asthma, croup, influenza, pneumonia, other acute lower respiratory tract infections, and/or other acute upper respiratory tract infections. We used dissemination areas (DA) as geographic units of analysis to aggregate all respiratory hospitalizations and ED visits and calculated smoothed standardized prevalence ratios (sSPR) by DA as the main outcome. Eigenvector spatial filters (ESF) were derived to identify areas with low to high sSPR. The association between geographic areas defined by ESF quintiles and sSPR values was estimated in a regression model including area-level SES, nitrogen dioxide (NO2), and particulate matter (PM2.5) as covariates.
Results: A total of 111,056 respiratory health services events were registered by the 119,909 children in the birth cohort. Geographic inequalities in respiratory health services utilization in both cities were identified. There were a 1.4-fold gap in Edmonton and a 1.5-fold gap in Calgary between the areas with the highest and the lowest smoothed SPR. This translates into 40% to 50% more pediatric respiratory health services events in urban areas spatially associated with the highest smoothed SPR compared to areas spatially associated with the lowest smoothed SPR. In Calgary, several small geographic conglomerates scattered across the city had a high demand of pediatric respiratory health services, while areas with a high demand for pediatric respiratory health services in Edmonton followed a regional-cluster spatial distribution.
Conclusion: There are geographic inequalities of respiratory health services utilization in Calgary and Edmonton that are independent of SES, NO2 and PM2.5. Research on other contextual factors (e.g., access to health care) underlying high demands of pediatric respiratory health services is needed.