Appropriate use of CT and MRI in British Columbia

Abstract

Background: Between 2004 and 2007 the number of CT and MRI examinations per 1000 people in BC increas ed by approximately 50%, a finding that raised concerns about the ap propriateness of the examinations. To address these concerns, the BC Ministry of Health commissioned a study of requests for CT and MRI in all health regions. Methods: An independent company considered expert in analyzing medical imaging data was contracted to assess 2000 randomly selected CT and MRI requisitions issued across BC between 2010 and 2011. The requisitions were analyzed using a five-point rating scale for appropriateness that was based on the Ca nadian Association of Radiologists guidelines and a meta-analysis of other guidelines. A computer program rated each requisition according to the appropriateness scale. Subsequently, a subset of the requisitions was reanalyzed by two independent reviewers. Results: In the computer analysis, 2% of the requisitions were rated “inappropriate,” while 46% were rated “indeterminate” because the computer program was not able to interpret the written portion of a significant number of requisitions. However, the two independent re viewers encountered no difficulties in assessing the appropriateness of each requisition in the data subset and found that only a small number of examinations were “indeterminate” and none were “inappropriate.” Conclusions: The results suggest that physicians in all regions of BC are requesting CT and MRI in compliance with established guidelines. In the computer analysis, CT and MRI orders rated “inappropriate” amounted to only 2% of all examinations, a figure considerably lower than an often quoted but poorly substantiated 30%. While the level of appropriateness found in BC orders for CT and MRI is acceptable, continued monitoring is needed and would be facilitated by the use of computerized physician order entry. Background According to the Canadian Institute for Health Information (CIHI), be tween 2004 and 2007 the number of computed tomography (CT) and magnetic resonance imaging (MRI) examinations per 1000 people in British Columbia increased by approximately 50%. 1 While these numbers can only be truly understood in the context of utilization in other provinces and other developed countries, the in crease raised concerns about the ap propriateness of these examinations. Objective data concerning the appropriateness of medical imaging tests have rarely been published. A widely quoted estimate that as many as 30% of imaging examinations are inappropriate is not supported by published data. 2-7 One Canadian prospec