Background Health inequalities are variations or differences in health that are systematic, socially produced and unfair. Despite an improved understanding of the causes of health inequalities, there is an overreliance on individual level interventions, often in the form of behaviour change or lifestyle interventions. It is increasingly recognised that in order to reduce health inequalities, there is a need to engage in more ‘upstream’ action. However, as action to reduce health inequalities becomes progressively more interdisciplinary, it is unclear the extent to which there is consensus as to what constitutes ‘upstream’ working to reduce health inequalities.

Methods The aim of this study is to examine interdisciplinary conceptualisations of upstream action to reduce health inequalities. Conceptualisations of upstream action have been identified through (i) a review of the literature and (ii) semi-structured interviews with researchers, practitioners and members of the public actively involved in research and practice to reduce health inequalities in the North West of England. This study is being undertaken as part of an MPhil/PhD study. Interviews and data analysis are ongoing.

Results There exist multiple different, but related, conceptualisations of upstream action. Examples include upstream action as any intervention focusing on prevention; ‘low agency’ or ‘population’ interventions; action on the social determinants of health; and grass roots or bottom up action that involves shifting the balance of power from individuals making decisions to individuals who are affected by decisions. There is a distinction that can be made between ‘upstream determinants’ of health and health inequalities, and ‘upstream action’, whereby people or interventions located ‘downstream’ can act to influence more upstream determinants of health inequalities.

Conclusion There is a need to further unpack, and clarify, what we understand by ‘upstream action’, and the ways in which such actions produce their effects, to assist researchers and practitioners to operationalise and embed these seminal ideas into their day to day practice.