Understanding the gap between need and utilization in outpatient care--the effect of supply-side determinants on regional inequities.

The present study analyzes the effect of supply-side determinants on regional inequities in outpatient care. Inequities are measured by the degree of disparity between need for and actual utilization of outpatient health services in the 412 German districts. Outpatient care needs of each district are determined by applying the regression model of the German risk structure compensation scheme. We find that supply-side factors account for half of the model's coverage of regional inequities. The remaining regional variance explained by the model may be attributed to socioeconomic and (socio-)geographic determinants as well as price effects. Our findings call for strengthening the role of GPs as coordinators in the health care system, countering the geographic maldistribution of physicians and introducing adequate programs to improve the level of care in socially deprived districts. The study also highlights the importance of differentiating between need, demand and utilization of health services in order to understand the root causes of inequities.