[Practice pattern and geographic variation in test ordering. A literature review].
OBJECTIVE
To review the available research results in order to identify evidence about geographical variation and practice variation in primary care in the diagnostic test ordering.


METHODS
Electronic databases, Medline, Cochrane Library, Science Direct, and Ingenta Select were used to find relevant English language publication between 1989 and 2004. Hand search and the reference lists search for publications were also applied. In addition, researchers were also contacted for publications. Quality of the studies were assessed by using criteria such as sound description of research methodology, detailed and clear presentation of study results.


RESULTS
There is a significant (2-4 fold) variation in laboratory test ordering between countries as well as between regions and praxis. There is larger (10-20 fold or more) variation between regions and praxis in the case of diagnostic tests which clinical usefulness is uncertain. The variation between diagnostic test ordering can be larger than variation between medical treatments or invasive interventions. Both geographical and praxis variation could be a result of multiple factors. None of the examined single factor alone was able to explain most of the variations.


CONCLUSIONS
Variation in diagnostic test utilisation is significant, and could be caused by multiple factors. Optimisation of diagnostic test ordering and promotion of appropriate utilisation may require multifaceted intervention throughout the health system including changes in regulation, licensing, available capacity, reimbursement/incentive systems and continuous medical education as well as better patient information.
Mogyorósy
Zsolt
Z
Centre for Health Economics, University of York, York, Egyesült Királyság.
Mogyorósy
Gábor
G
D003955:Diagnostic Tests, Routine / Q000706:statistics & numerical data*; D006801:Humans; D006814:Hungary; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*