How can healthcare standards be standardised?

International travel, medical tourism and trade have created a demand for reliable assessment of healthcare provision across borders, and for information which is accessible to patients, insurers and referring institutions. External assessment schemes for healthcare providers may be clustered into three types: statutory regulation and institutional licensing, International Standardization Organisation certification, and voluntary systems such as peer review and healthcare accreditation. Increasing complexity of healthcare provision, pressures for public accountability and expectations of professional self-governance place a burden on the inspectors and the inspected. If only to contain costs of external assessment and to increase access to reliable information for patients and insurers, the three approaches must work together rather than compete. This paper summarises the origins, aims, authority and methods of the three general models, describing current pressures and opportunities for convergence (between systems and across borders) in the UK and in Europe.