[Determining the health status of a population: role and quality of survey questions].

Measuring population health levels: role and quality of interview data. Role and quality of interview data are examined with respect to their importance for the measurement of population health levels. Starting from general information requirements in health services, the contribution of population survey data is described. Interview data constitute just a subset of such survey data. When role and quality of interview survey data are to be judged, survey methods are of major importance. They not only determine the quality but also the role of health interview survey data in the framework of all information about the population's health. If this is so, efforts to improve health survey data quality should not only be directed towards improvement of traditional methodological aspects (such as sampling procedures and response rates) but also towards the implementation of prerequisites for wider usage of health interview data. This may be achieved by improving their linkage potential, by implementing uniform minimal basic data sets, by introducing identical terms and definitions and by keeping identical terms and definitions and by keeping identical survey methods (including questions) for several years in a row. Quality of health interview data is, therefore, determined by the methodological standards underlying their collection and the potential for usage of these data sets determines the role they play as part of the information about the population's health.