Inequities in diabetes prevalence at the intersection of sex, age, place of birth and education

Abstract Background Health inequities remain a global public health challenge; the intersectional approach emphasises that these inequities result from the complex interplay of multiple social factors and power dynamics. The burden of type 2 diabetes mellitus (T2DM) can be better understood through an intersectional lens that considers peoples’ diverse socioeconomic position, identities, and experiences of multiple marginalisation. This study aims to analyse T2DM prevalence at the intersection of sex, age, place of birth, and education, to uncover overlapping dynamics of inequities. Methods We selected all Piedmont (Italy) residents aged 40-70 as of 31/12/2016. Prevalent T2DM cases were identified using a validated algorithm. Individuals were stratified by all combinations of sex, age, place of birth, and education. Multilevel Analysis of Individual Heterogeneity and Discriminatory Accuracy models were applied to assess the effect of intersectionality on the T2DM prevalence through the estimation of the Variance Partition Coefficient (VPC) and the Proportional Change in Variance (PCV). Results Among the 1,782,854 individuals included in the study (102,935 T2DM cases), the predicted percentage of T2DM in the different strata ranged from 0.60% (among Italian women <50 years with high education) to 24.7% (among women from North Africa aged 61-70 with low education). Men aged 61-70 years with Asian or North-African origins showed a high prevalence of T2DM regardless of education level. A VPC of 18.3% indicated a relatively large amount of clustering at stratum-level. In the full model, the PCV was 93.5%, suggesting that the remaining 6.5% was attributable to an intersectional effect. Positive and negative significant interaction effects were observed only for a small number of strata. Conclusions Results contribute to improving the understanding of the heterogeneous distribution of risk and the social dynamics that generate conditions of vulnerability to adverse health outcomes. Key messages • The presence of acknowledged protective factors, such as an high level of education, does not sufficiently mitigate the disadvantages associated with being immigrant for certain populations. • Results highlight the importance of operationalising intersectionality to go beyond siloed approaches and understand how inequities emerge through multiple and intersecting social dimensions.