Stratification of radiological test ordering: its usefulness in reducing unnecessary tests with consequential reduction in costs.

This study examines the effectiveness of an automated, stratified system of radiological test ordering, known as 'Traffic Lights', in reducing the number of unnecessary tests and their associated costs. The system involves stratification of radiological tests into three groups, denoted by red, amber and green colours. 'Red' tests must be authorized by a consultant. 'Amber' tests must be signed by a registrar or authorized by a consultant. 'Green' tests can be ordered directly by residents or interns. In the 4 months after the introduction of 'Traffic Lights', each radiological method showed a reduction in both the number of tests and their associated costs. The reduction was consistent across both medical and surgical groups. Analysis of data 20 months immediately after the introduction of 'Traffic Lights' also showed a consistent reduction in the total number of tests, suggesting that the changes are sustainable and unlikely to be due to seasonal variation. Combined with evidence-based medicine protocols, this stratified system of radiological test ordering should ensure the safety, quality and appropriateness of imaging tests and minimize overall patient radiation dose.