‘Us and them’: A realist interview study exploring how and why health system factors influence dentists’ participation in state funded, contracted primary dental care for low-income populations in Ireland

Objectives: To identify and explain the health system factors influencing private general dental practitioners (GDPs) engagement in state-funded, contracted primary oral healthcare for low-income adults in Ireland, in which circumstances, for which groups, how and why. Methods: Nineteen realist interviews were conducted with frontline GDPs, health system actors and academic subject experts from Ireland and elsewhere. Collected data were then transcribed, coded, and analysed to generate context–mechanism–outcome configurations (CMOCs) and develop an overarching realist programme theory to explain causation. Results: Thirteen individual and abstracted CMOCs were crafted and subsequently consolidated into five high level CMOCs. GDPs’ engagement with state funded care is influenced by a myriad of complex health system contextual factors. These include low political and resource commitment to oral health; cost containment measures characterised by limited and outdated baskets of care and low remuneration; overtly bureaucratic oversight or contract administrative processes; adversarial communications and the absence of consultative mechanisms between the health system and GDPs. Other factors such as oral healthcare ‘market’ dynamics, GDPs’ professional networks and community ties can also influence engagement in state care. Conclusion: As Ireland looks to reform its primary oral healthcare system to widen population access to care and meet national oral health policy and WHO commitments on oral health, the findings of this study provide health system leaders with evidence to leverage system change and increase or sustain GDPs’ engagement in state care. Leveraging such change has the potential to improve access to care for vulnerable populations and reduce oral health inequalities.