[Sex and gender: five challenges for epidemiologists]

This paper explores the challenges posed by sex and gender for epidemiologists as they try to integrate sex and gender concerns into their work in more appropriate and effective ways. The first challenge is one of conceptual clarification with considerable confusion still surrounding the use of the terms sex and gender themselves. The second challenge is to develop a broader understanding of the links between biological sex and health. The third challenge is to create a more comprehensive understanding of the ways in which social gender shapes the health of both women and men. The fourth challenge is to ensure that all research designs are both sex and gender sensitive. And the final challenge is to find a strategy for integrating findings on both sex and gender into wider equality agendas. This paper will examine each of these challenges in turn.