Assessing childhood health outcome inequalities with area-based socioeconomic measures: a retrospective cross-sectional study using Manitoba population data

Socioeconomic gradients in health exist in Canada. Although multiple Canadian area-based socioeconomic measures (ABSM) have been developed, none have been specifically validated against pediatric outcomes. Our objective was to compare the strength of association between key pediatric health outcomes and a number of ABSM, including income quintile. This was a retrospective cross-sectional assessment of the association between socioeconomic status (SES) measured by ABSM and 20 specific pediatric health outcomes. Data from the Manitoba Population Research Data Repository were used for residents aged 0–19 years from 2010 to 2015. Outcomes included birth-related events (e.g. mortality), vaccination uptake, hospitalizations, and teen pregnancy. Regression goodness of fit was used to assess the strength of individual associations. Inequality was measured by slope index of inequality (SII) and relative index of inequality (RII). Overall, 19 of 20 outcomes had socioeconomic gradients identified by SII and RII. The multidimensional CAN-Marg indices had the best explanatory power in standard regression models. The simplest ABSM—income quintile—detected 16 of 19 confirmed inequalities, more than any other single measure. At all ages, many pediatric health outcomes in Manitoba were associated with significant socioeconomic inequalities; while income quintile detected most, CAN-Marg composite indices had the best explanatory power.