Socioeconomic inequalities in 29 childhood diseases: evidence from a 1,500,000 children population retrospective study

Background Socioeconomic position (SEP) powerfully affects health status in the childhood population. However, the knowledge of which diseases are more affected by SEP and whose outcomes could be improved by having a more equitable society remains uncertain on a population basis. Methods We measured socioeconomic and gender inequalities in the pre-COVID-19 era for 29 diseases in the entire childhood population in Catalonia to identify which diseases are most impacted by inequalities. This population-based study included 1,449,816 children under 15 years old from 2014 to 2017 (48.52% girls) and each of their registered diagnoses within the Catalonia National Health System. We calculated frequency measures by SEP and their sex ratios for each disease. We estimated four regression-based inequality measures: slope index of inequality, relative index of inequality (RII), absolute population-attributable fraction, and population-attributable fraction. Results Twenty-five of the 29 diseases examined showed SEP inequalities. The diseases with the greatest inequalities in both sexes were tuberculosis, obesity, adjustment and anxiety disorders, essential hypertension, poisoning, short gestation, low birth weight, foetal growth retardation and intrauterine hypoxia and birth asphyxia and trauma (RII ≥ 2.0); only food allergy showed the opposite pattern (RII p p Conclusions Socioeconomic and gender inequalities are widely present in childhood health. This indicates that SEP plays a common role in their development although it varies in magnitude according to each disease. It is also a phenomenon that comprises all SEP groups in society. Action needs to be taken to ensure a fairer start in life in terms of health.