[Incidence of operations in Germany via telephone survey in 4 selected cities].

Considerable regional variation of surgical procedure rates has been reported for a number of countries. Influential variables that have been discussed are patient-related, physician-related and health care system-specific factors. A representative computer-assisted telephone survey was conducted in four selected regions for a study sponsored by the German Federal Ministry of Health. These regions were the townships of Aachen and Hamm in North Rhine-Westphalia and Chemnitz and Görlitz in Saxony. During the telephone survey 1897 persons were contacted and 1041 interviews completed. Multiple logistic regression showed a surgical procedure frequency which was by 40% higher in Aachen than in Hamm. During further analysis the regional localisation was replaced by region-specific structural health care information variables. During this analysis the regional frequency of medical specialists was significant at a 5% level (odds ratio: 1.07; 95% confidence interval: 1.02-1.12). This result can be interpreted as an increase in surgical procedures by 7% for each additional specialist per 10,000 persons. However, no definite conclusion can be reached based on the available data. Intensifying the presented survey-based health services research has the potential to identify regional over- or undersupply of medical services, to objectify and accompany informational, administrative or political action and thereby to support equity in access and health care in the sense of an optimized allocation of resources.