The implementation of the British National Health Service in 1948 as a system based on generalists, with general practitioners as the gatekeepers to secondary care, institutionalised the separation of primary and secondary care. Since then it has proved a cost effective model,1,2 emulated by several health maintenance organisations in the United States in an attempt to contain costs.3 Now, however, the internal market is raising questions about the separation of primary and secondary care and may undermine a key component - the referral of a patient by a general practitioner for advice on diagnosis or management by a specialist.

Two elements of the reforms in particular are changing the relation between primary and secondary care. Firstly, the shift of emphasis from secondary to primary care has altered the historical imbalance in the relationship between general practitioners and specialists. Primary care now has a pivotal role in the NHS, and the new commissioning arrangements give general practitioners the power to plan and manage more directly their patients' care. Contracting encourages interaction between general practitioners and hospitals, …