Variations in activity and practice patterns: a French study for GPs.

<bold>Objectives: </bold>To identify the different practice profiles of general practitioners (GPs) in order to test the hypothesis of heterogeneity in physician behaviour.<bold>Data: </bold>For the year 2000, 4,660 GPs from two regions in France.<bold>Variables: </bold>volume and structure of the physicians' medical activity, income level, personal characteristics, socioeconomic and geographical environment, characteristics of their patients.<bold>Methods: </bold>A cluster analysis to identify different practice profiles and a regression analysis to display the determinants of the physicians' activity.<bold>Results: </bold>Four different homogeneous groups can be identified, each one associating a physician's level of activity to his socioeconomic status. The level and the intensity of medical activity depend on individual factors, patients' characteristics as well as the socioeconomic context.<bold>Conclusions: </bold>There is no uniformity in the way GPs practice medicine. An immediate consequence is that any cost-containment measure that is applied uniformly to all GPs inevitably results in different outcomes according to the physicians' category type. [ABSTRACT FROM AUTHOR]