Surveillance of stroke: a global perspective.

For preventive strategies to be efficient, it is essential to have information on the pattern of disease and exposure to major risk factors that predict future diseases in the population. Basic epidemiological data such as mortality rates are reported for less than one-third of the world's population and are almost exclusively from developed countries. However, it is the developing countries, particularly those in rapid economic and demographic transition, which will experience a major rise in ageing-related diseases. The World Health Organization is intensifying the development and implementation of simple, sustainable surveillance systems that can be used in many different settings around the world. Unlike heart disease and cancer, stroke is a clinically defined disease, which makes it possible to identify trends in different countries irrespective of access to technological equipment. A stepwise approach to increasing detail in the data to be collected for surveillance of stroke is suggested. This will allow countries with different levels of resources and capacity in their health systems to collect useful information for policy.