Health gradients in emergency visits and hospitalisations for paediatric respiratory diseases: A population-based retrospective cohort study

Background Socio-economically deprived children face a disproportionate burden of respiratory diseases. The association between area-level material and social deprivation and emergency department (ED) visits and hospitalisations for paediatric respiratory diseases has not been explored. Objectives We evaluated health inequalities in emergency department (ED) visits and hospitalisations for paediatric respiratory diseases according to material and social deprivation indexes. Methods This population-based retrospective cohort study deterministically linked birth, ED visits and hospitalisation data, and census-based, area-level deprivation indexes for all singleton children born in the province of Alberta, Canada, between 2005 and 2010 who had at least one recorded ED visit or hospitalisation for respiratory diseases in their first five years of life. We classified ED visits and hospitalisations for seven respiratory diseases by deprivation indexes. Concentration indexes (CInd) and area-level concentration curves measured health gradients across deprivation groups. Rate ratios (RR) evaluated associations between deprivation indexes and respiratory episodes of care. Results The study cohort included 198 572 newborns. The highest CInd were found in ED visits for other acute lower respiratory tract infections (oLRTI; CInd -0.22, 95% confidence interval [CI] -0.32, -0.12) and bronchiolitis (CInd -0.21, 95% CI -0.29, -0.12), and for pneumonia hospitalisations (CInd -0.23, 95% CI -0.33, -0.13). Croup ED visits had a low inequality degree. Compared to social deprivation, the material deprivation index presented a more consistent health gradient of increased episodes of care with increasing deprivation. oLRTI ED visits (RR 2.60, 95% CI 2.34, 2.92) and pneumonia hospitalisations (RR 2.57, 95% CI 2.31, 2.86) presented the largest inequalities between the least and most materially deprived groups. Conclusions We found a concentration of ED visits and hospitalisations for paediatric respiratory diseases in the most deprived groups. However, health inequalities are present across the material and social deprivation spectrum. Compared to the social deprivation index, the material index presented clearer paediatric respiratory health gradients.