Clinical decision making, medical practice variation, and social disaparities in primary care: The role of organizational context.

Abstract

Medical practice variation and social disparities in health are pervasive features of health care systems. But what impact might everyday clinical decision making have in shaping such aggregate patterns, and could this in turn be influenced by the immediate environment in which family doctors practise? We investigate this by studying inter-practitioner variation in clinical activity across four payment types in New Zealand, a “gatekeeper” primary care system. We do this for four measures of clinical activity by patient ethnic and socio-economic status in a 2001/2 representative sample of 9,272 encounters at 185 family practices. Initial analysis showed little variation in levels of clinical activity either by patient status or by practice type. However, with the application of multi-level statistical techniques it was evident that, while there was still little systematic difference in physician activity rates by patient status, inter-practitioner variation was greater for patients of ethnic minority background and from socio-economically deprived areas. Furthermore, this variability was particularly marked in fee-for-service practice settings. These results provide some support for the notion that clinical decision making in primary care may be associated both with patient social status and with practice environment, although this seems to be more a matter of variation in clinical activity around a common mean rather than indicative of a systematic difference in service levels between patient groups.