Cohort studies around the world: methodologies, research questions and integration to address the emerging global epidemic of chronic diseases.

With ageing populations, increased economic prosperity and the ensuing lifestyle changes, there has been a dramatic increase in the burden of chronic non-communicable diseases in countries of the developing world. The distribution of risk factors for chronic diseases among populations in developing countries has traditionally been very different from that in their Western counterparts, thus resulting in considerable variation in disease distribution in these settings. However, with the increase in globalization along with rapid advancements in technology, many developing countries are now faced with the challenge of a dual disease burden, battling existing communicable infectious diseases as well as the emerging epidemic of non-communicable chronic diseases. This paper highlights the need for multiple cohort studies on chronic diseases around the world, and explores some of the challenges in establishing and maintaining these studies in resource-constrained settings. Copyright Â