Surveillance in developed countries with particular reference to child growth.

Surveillance of biological function rather than of disease events is a possible method of detecting early changes in population health. The reasons for and methods of a pilot surveillance scheme of the growth of schoolchildren in Britain are discussed. The study, started in 1972, supports the feasibility of surveillance using simple growth measurements and information provided by parents on self-administered questionnaires. Other possible applications of this type of surveillance include growth and nutrition at other stages of life as related to nutrition intervention programmes, and respiratory function as related to environmental changes or the introduction of new substances such as 'safer' cigarettes.