Inequalities in paediatric hospitalisations for costly and prevalent conditions in Ontario, Canada: a population-based cohort study

Background Identifying inequalities is important for informing research, and policy efforts to reduce health disparities. This study measured the inequalities in hospitalisations for the costly and prevalent conditions in hospitalised children using association estimates. Methods Population-based cohort study using health administrative databases in Ontario, Canada between 2014 and 2019. The hospitalisation rate was determined for the costly and prevalent conditions in children. Hospitalisation inequalities by four equity stratifiers (material resources, rurality, sex, and immigrant status) were quantified using rate difference (RD), rate ratio (RR), and ratio of excess to total hospitalisation rate. Multivariable logistic regression analyses were also conducted. Findings In a population of 3.7 million children (median age 7.0 years, Interquartile range: 1.0-12.0), there were 612,597 hospitalisations. Large inequalities comparing children among least versus most resourced quintile was observed in low birth weight (RD: 1,823.3 hospitalisations per 100,000 children, 95% CI: 1,662.7, 1,983.9). Conditions with large inequalities comparing rural versus urban areas included low birth weight (RD: -1,833.2 hospitalisations per 100,000, 95% CI: -2,012.8, -1,653.6); and drug withdrawal syndrome in newborn (RR: 1.9, 95% CI: 1.7, 2.1; adjusted odds ratio (aOR): 1.4, 95% CI: 1.2, 1.5). Conditions with large inequalities comparing males versus females included low birth weight (RD: -888.3 hospitalisations per 100,000, 95% CI: -992.5, -784.02); and anorexia nervosa (RR: 0.08, 95% CI: 0.07, 0.10; aOR: 0.1, 95% CI: 0.1, 0.1). Conditions with large inequalities comparing non-refugee immigrants versus non-immigrants included major depressive disorder (RR: 2.8, 95% CI: 2.7, 2.9), and comparing refugees versus non-immigrants included drug withdrawal syndrome in newborn (RR: 0.09, 95% CI: 0.05, 0.15). Results from multivariable analyses were similar. Interpretation Newborn and mental health conditions had the largest inequalities in hospitalisations by the equity stratifiers. Findings from this study can be used to prioritise future health equity research to reduce health inequalities.