<p>This research investigates the role of health practitioner regulation in health service improvement. Over the last 25 years, service improvement has included management reforms, quality and redesign programmes, multidisciplinary teamwork, the integration of clinical information systems, and new roles for health professionals. Yet despite sustained effort, improvements tend to be localised rather than organisation or system-wide. Remedies have included attention to leadership, change management and service culture. Through the same period, there have been changes to expand and strengthen health practitioner regulation, but scant attention to whether this regulation could contribute to difficulties with health service improvement. A critical realist methodology was used to build an explanation of how regulatory policies could condition health professionals and health service organisations in ways that limit the progress of service improvement. A multilevel approach was used to discover the mechanisms that could operate among policy-makers and the health workforce, generating effects in health service organisations. The study concluded that this explanation contributes new insights to explain persistent difficulties in health service improvement. The research began with the 19th century to understand the social conditions in the construction of the health workforce and health service organisations. Next, it identified the network of modern regulatory stakeholders in healthcare, along with the potential for their policies to operate in conflict or concert depending on the circumstances. Deficiencies were identified in the traditional accounts of health practitioner regulation, which assumes a single profession and sole practice. ‘Regulatory privilege’ was developed as an alternative theory that describes the operation of nine historically constructed regulatory levers among the multiple health professions employed in health service organisations. This theory linked the regulatory and practice levels, to observe the interactions between health practitioner regulation and policies for health service improvement. Drawing on the recent history of health reforms, eight elements were identified that characterise directions for service improvement in healthcare. Investigation of interactions between these nine levers and eight elements identified sources for policy interactions through six sector levels. Interactive effects were identified in: policy design influenced by health practitioner regulation; the leadership and management capability in health service organisations, the design options for delivery of services, the means available to coordinate services, the role opportunities and practice arrangements for health professionals, and the experience of service fragmentation by consumers. This multilevel explanation shows how health practitioner regulation could contribute to difficulties with service improvement, even when health services have adopted best practice in their implementations. It shows how poor alignment between the regulatory and practice levels makes it unlikely that health service organisations could address certain difficulties in the ways suggested by some scholars. Given the sustained directions for health service improvement, these findings could contribute to policy thinking around how to better align the regulatory and practice levels to realise organisation or systemwide improvements in the delivery of healthcare.</p>
