State of the art in research on equity in health.

This essay provided the introduction to a workshop in Bellagio, Italy, on the subject of translating research into policy for equity in health. The essay first defines equity in a way that facilitates its assessment and monitoring and then summarizes evidence from existing research. Directions for developing policy strategies follow from these principles. The role of health services in influencing the distribution of health in populations is discussed in the special context of primary-care-oriented health systems that are, at the same time, more effective, more efficient, and more equity producing than is the case for specialist-dominated health systems.