This report was commissioned by the English Department of Health to inform the process of regulatory reform. It addresses two key questions related to assuring the quality of medical practice in a comparative context: how doctors' continuing competence is assessed and how poor medical practice is detected and what action is then taken. The research method was to select seven countries with advanced health care systems but different forms of funding. Using existing literature, web-based data and personal contacts, country/state profiles were developed to address the key questions in each country. A cross-country analysis identified a trend towards assessing competence on a regular basis with an emphasis either on continuing education or on regular performance assessment for revalidation, using different techniques. Three different models for identifying and acting on poor performance were identified. In conclusion, the report identified good practice and the choices open to policy makers in the context of the regulatory system in England.