Population-based health monitoring via computer-assisted telephone interviews in Bavaria

From June 1999 until May 2000, 2051 computer-assisted telephone interviews concerning health and health related behaviours were assessed in Bavarian h ouseholds. The aim of the study was the evaluation of the validity and repr esentativity of this data by a comparison of selected variables from the Ba varian Mikrozensus-survey 1999. The distribution patterns of the marital st atus, the size of the households, the gainful employment, the household-net to-income, the school qualification and of the smoking status correspond we ll with those of the Mikrozensus 1999. As often found in questionnaire base d surveys, a disproportionately high rate of participation of highly educat ed persons was observed. This led to an effect only in terms of a too small rate of persons with a low household-netto-income. Within the study, two d ifferent designs were compared. The commitment of the telephone numbers to a gender for an equal quotation of men and women led to an underrepresentat ion of single-households and therefore also of unmarried persons, but it ha d no effect on the other characteristics. The results of this study show, t hat the method of computer assisted-telephone interviews is a valid and che ap basis for the establishment of an exhaustive health surveillance system in Germany.