Fundamental causation and candidacy: Harnessing explanatory frames to better understand how structural determinants of health inequalities shape disengagement from primary healthcare

This paper aims to better understand how structural determinants of health inequalities shape disengagement from healthcare for vulnerable groups across a range of social conditions. Using a sub-sample (N = 20) from a qualitative interview UK study of those missing from primary-care, it illuminates how structural drivers of health inequalities operate at organisational and practice levels to weaken engagement with primary-care. Finding ways of better analysing and demonstrating the causal chains between structural determinants and patterns of disengagement is important because previous research has shown that practitioner and policy understanding of structural determination, an important precursor for mitigatory action, is not always sufficient, and research on healthcare utilisation can itself be weak in investigating structures of inequality. We address this deductively by testing a novel combination of Link and Phelan's Fundamental Cause Theory and Dixon-Woods and colleagues' Candidacy framework. Combining elements of these frameworks compensates for identified gaps in each. We demonstrate how Candidacy can be strengthened through incorporating more systematic theorisation of structural processes and that the more abstract arguments of fundamental (structural) causes can be made concrete via Candidacy's focus on inequalities in patients' access to, and utilisation of, healthcare. We also argue that both theories are enhanced by including Metzl and Hansen's concept of 'structural competency' as a potential mitigatory mechanism operating between fundamental causes and patient engagement.