Assessment of the cost-effectiveness of magnetic resonance including diffusion-weighted brain imaging in patients with transient ischaemic attack and minor stroke
For accurate diagnosis of transient ischaemic attack (TIA) and mini-stroke, computed tomography (CT) and magnetic resonance imaging (MRI) are two types of scanning that are available. CT is less expensive but more widely available. However, it is not very good at detecting ischaemic strokes, the commonest type of mini-stroke. MR diffusion-weighted imaging (MR DWI) is newer, more expensive and good at showing the ischaemia, but is often not available for people with mini-stroke. There is a lack of research evidence on whether greater use of MR DWI would lead to better patient care and fewer strokes. This project addressed this research gap by conducting a systematic review and economic model of the cost-effectiveness of MR DWI relative to CT. We found that, compared with a policy of 'CT scan all patients', MR was not cost-effective, except for patients presenting at > 1 week after symptoms to diagnose haemorrhage. Strategies that triaged patients with low ABCD2 scores for slow investigation or treated DWI-negative patients as non-TIA/minor stroke prevented fewer strokes and increased costs. Further, 'one-stop' CT/MR angiographic-plus-brain imaging was not cost-effective.
Outcome and Translation
The project will inform the development of future evidence-based guidelines for the diagnosis of TIA and mini-stroke in the UK, through dissemination of published outputs within the appropriate clinical networks.
External Collaborators: JM Wardlaw, M Brazzelli, M Dennis, P Sandercock, J de Wilde, (University of Edinburgh); M Brazzelli (HSRU, University of Aberdeen); K Muir and D Hadley (University of Glasgow)
Brazzelli, M., Shuler, K., Quayyum, Z., Hadley, D., Muir, K., McNamee, P., De Wilde, J., Dennis, M., Sandercock, P. and Wardlaw, J.M. (2013) 'Clinical and imaging services for TIA and minor stroke: results of two surveys of practice across the UK', BMJ Open, 3(8).
Wardlaw, J., Brazzelli, M., Miranda, H., Chappell, F., McNamee, P., Scotland, G., Quayyum, Z., Martin, D., Shuler, K., Sandercock, P. and Dennis, M. (2014) 'An assessment of the cost-effectiveness of magnetic resonance, including diffusion-weighted imaging, in patients with transient ischaemic attack and minor stroke: a systematic review, meta-analysis and economic evaluation', Health Technology Assessment, 18(27).
Brazzelli, M., Dennis, M., McNamee, P., Quayyum, Z., Shuler, K. and Wardlaw, J. (2012) 'Clinical and imaging services for secondary stroke prevention after suspected TIA or minor stroke in the UK', XXI European Stroke Conference, Lisbon, Portugal, 22-25 May 2012.
Brazzelli, M., Dennis, M., McNamee, P., Miranda, H., Quayyum, Z., Shuler, K. and Wardlaw, J. (2012) 'Are imaging and clinical services for secondary stroke prevention after TIA or minor stroke adequate in the UK? ', 36th European Society of Neuroradiology Annual Meeting, Edinburgh, 21-23 September 2012.