My research is on health systems. The emphasis is on the organization of primary care. My research is about the Netherlands and the comparison with other European countries. I do this research among others based on data we collected in a large international project in 34 countries, the QUALICOPC study. We combined information about the health care system, data about general practitioners and their practices, and the experiences of patients about the consultation they had with their general practitioner. In another project we look at the transferability of innovations in the organization of health services and health care policies between countries. This is part of a larger international project with the aim of formulating a research agenda for health services and system research.

I also do research into the relationship between the environment in which people live and their health. This started with research into the relationship between a green living environment and people's health. Later I have extended this to other aspects of the physical environment, such as air pollution, and the social environment, such as social capital. With Nivel Primary Care Database, we have a wonderful infrastructure for analysing the relationships between the living environment and the health problems that people present their GP.