A lifecourse perspective on sociodemographic intersectional inequalities in physical and mental health outcomes

Persistent inequalities in health outcomes continue to be a stubborn feature of many developed Western societies. To effectively understand health inequalities researchers must address two key criticisms: an overt focus on singular dimensions of disadvantage and a continuing need for longitudinal studies. Lifecourse intersectionality offers a framework to address these critiques through situating more nuanced and multidimensional understandings of the development of inequalities over time. We conduct a longitudinal Multilevel Analysis of Individual Heterogeneity and Discriminatory Accuracy (MAIHDA) examining both physical and mental health SF12 scores using UK Household Longitudinal Study data for adults (2009 to 2023). Forming intersections based on sex, ethnicity, generational cohort, education, and socioeconomic class, we identify a substantial degree of intersectional variation in our outcomes, and distinct differences in the development of intersectional inequalities in physical and mental health over the lifecourse. Intersectional inequalities are more pronounced for mental health compared to physical health, particularly at younger and older ages. In both cases, inequalities are additively patterned with generation and sex appearing most important to mental health and socioeconomic differences being stronger for physical health. However, our results also emphasise heterogeneity in the identified lifecourse intersectional effects, particularly in relation to how the patterning of the sociodemographic components for mental health vary by generational cohort. We therefore help reveal important complexity in the development of health inequalities in the UK and highlight the utility of longitudinal intersectional MAIHDA as a tool for quantitative intersectional researchers.