Accountability displacement in health systems integration: A study of the English National Health Service

Governing complex public services increasingly requires coordination across multiple organisations, yet the collaborative arrangements intended to achieve this create new governance and accountability challenges. In England, the National Health Service (NHS) has pursued successive reforms to better integrate the planning and delivery of health and care. The most recent Health and Care Act 2022 aimed to strengthen horizontal accountability mechanisms by establishing a statutory basis for Integrated Care Systems (ICS) and enabling organisations to delegate responsibilities to each other locally to achieve subsidiarity. However, the Act did not particularly change vertical accountability mechanisms and lacked guidance on how horizontal accountability should operate. This paper explores what happens when a metagovernor simultaneously promotes horizontal collaboration and enforces vertical oversight, and through what process one accountability mechanism prevails over another. We analysed the formal governance structures in all 42 Integrated Care Board (ICB) governance handbooks and conducted 17 semi-structured interviews with ICB directors of strategy. Our findings reveal that ICBs faced conflicting accountability demands from NHS England, and that stronger felt accountability towards vertical mechanisms consistently outweighed horizontal ones. Most ICBs retained decision-making authority, resulting in limited delegation and weak horizontal accountability. We conceptualise these dynamics as accountability competition, where vertical and horizontal mechanisms coexist and create tension, and accountability displacement, where stronger hierarchical controls crowd out collaborative forms of accountability. We conclude that without clearer policy guidance, the prevailing hierarchical context will continue to prevent the development of effective horizontal accountability, undermining the collaborative aims of the Act.