Health indicators: building blocks for health situation analysis.

• Epidemiological Surveillance System for Acute Pesticide Poisoning The availability of information based on valid, reliable data is a sine qua non condition for the analysis and objective evaluation of the health situation, evidence-based decision-making and programming in health. The search for objective measures of a population’s state of health is an old tradition in public health, particularly in epidemiology. Starting with the works of William Farr in the 19th century, health descriptions and analyses were, for a long time, based on measures of mortality and survival.1,2 The need for considering other dimensions of a population’s health status was recognized more recently. This realization came in part as a result of the successful control — mostly in the most industrialized areas — of infectious diseases that were traditionally responsible for the greatest burden of mortality. It is also the product of a more comprehensive vision of health and its population determinants. As a consequence, measures of morbidity, disability and non-biological determinants of health (such as access to services, quality of care, living conditions and environmental factors) are increasingly necessary to document people’s capacity to function physically, emotionally and socially, as well as to objectively analyze the health situation (See figure 1).3 Health indicators facilitate the quantification and evaluation of these different dimensions of a population’s health.