[Availability and quality of necessary data for establishing health assessment in the canton of Geneva: implications for the monitoring of the development of problems and impact of health policies].

The global health assessment of the population of the canton of Geneva, based on the WHO's 38 "Health-for-ALL" targets, shown several gaps in the health information system. The quality of the available data is discussed in regard of various criteria (type of statistics, representativeness, frequency of data collection, diffusion, comparability, concern for validation). Two examples are presented: 1.) The incidence of low birthweight shows how a hospital-based statistics indicator can accurately reflect a trend over time, but provide a biased estimation of a risk level. 2.) The evolution of several indicators concerning drug consumption shows how important it is to validate these indicators in order to allow an adequate interpretation. Such a validation is seldom made. The present situation could be improved by a more efficient structure of the canton's health statistics.