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

Joanna Wardlaw, Miriam Brazzelli, Hector Miranda, Francesca Chappell, Paul McNamee, Graham Stewart Scotland, Zahid Quayyum, Duncan Martin, Kirsten Shuler, Peter Sandercock, Martin Dennis

Research output: Contribution to journalArticle

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Abstract

BACKGROUND: Patients with transient ischaemic attack (TIA) or minor stroke need rapid treatment of risk factors to prevent recurrent stroke. ABCD2 score or magnetic resonance diffusion-weighted brain imaging (MR DWI) may help assessment and treatment.

OBJECTIVES: Is MR with DWI cost-effective in stroke prevention compared with computed tomography (CT) brain scanning in all patients, in specific subgroups or as 'one-stop' brain-carotid imaging? What is the current UK availability of services for stroke prevention?

DATA SOURCES: Published literature; stroke registries, audit and randomised clinical trials; national databases; survey of UK clinical and imaging services for stroke; expert opinion.

REVIEW METHODS: Systematic reviews and meta-analyses of published/unpublished data. Decision-analytic model of stroke prevention including on a 20-year time horizon including nine representative imaging scenarios.

RESULTS: The pooled recurrent stroke rate after TIA (53 studies, 30,558 patients) is 5.2% [95% confidence interval (CI) 3.9% to 5.9%] by 7 days, and 6.7% (5.2% to 8.7%) at 90 days. ABCD2 score does not identify patients with key stroke causes or identify mimics: 66% of specialist-diagnosed true TIAs and 35-41% of mimics had an ABCD2 score of ≥ 4; 20% of true TIAs with ABCD2 score of < 4 had key risk factors. MR DWI (45 studies, 9078 patients) showed an acute ischaemic lesion in 34.3% (95% CI 30.5% to 38.4%) of TIA, 69% of minor stroke patients, i.e. two-thirds of TIA patients are DWI negative. TIA mimics (16 studies, 14,542 patients) make up 40-45% of patients attending clinics. UK survey (45% response) showed most secondary prevention started prior to clinic, 85% of primary brain imaging was same-day CT; 51-54% of patients had MR, mostly additional to CT, on average 1 week later; 55% omitted blood-sensitive MR sequences. Compared with 'CT scan all patients' MR was more expensive and no more 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. 'One-stop' CT/MR angiographic-plus-brain imaging was not cost-effective.

LIMITATIONS: Data on sensitivity/specificity of MR in TIA/minor stroke, stroke costs, prognosis of TIA mimics and accuracy of ABCD2 score by non-specialists are sparse or absent; all analysis had substantial heterogeneity.

CONCLUSIONS: Magnetic resonance with DWI is not cost-effective for secondary stroke prevention. MR was most helpful in patients presenting at > 1 week after symptoms if blood-sensitive sequences were used. ABCD2 score is unlikely to facilitate patient triage by non-stroke specialists. Rapid specialist assessment, CT brain scanning and identification of serious underlying stroke causes is the most cost-effective stroke prevention strategy.

FUNDING: The National Institute for Health Research Health Technology Assessment programme.

Original languageEnglish
Pages (from-to)1-368, v-vi
Number of pages368
JournalHealth Technology Assessment
Volume18
Issue number27
DOIs
Publication statusPublished - Apr 2014

Fingerprint

Transient Ischemic Attack
Cost-Benefit Analysis
Meta-Analysis
Magnetic Resonance Spectroscopy
Stroke
Costs and Cost Analysis
Neuroimaging
Tomography
Biomedical Technology Assessment
Triage
National Institutes of Health (U.S.)
Brain
Expert Testimony
Secondary Prevention

Keywords

  • Aged
  • Cost-Benefit Analysis
  • Diffusion Magnetic Resonance Imaging
  • Female
  • Humans
  • Ischemic Attack, Transient
  • Male
  • Middle Aged
  • Neuroimaging
  • Stroke
  • Tomography, X-Ray Computed

Cite this

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. / Wardlaw, Joanna; Brazzelli, Miriam; Miranda, Hector; Chappell, Francesca; McNamee, Paul; Scotland, Graham Stewart; Quayyum, Zahid; Martin, Duncan; Shuler, Kirsten; Sandercock, Peter; Dennis, Martin.

In: Health Technology Assessment, Vol. 18, No. 27, 04.2014, p. 1-368, v-vi.

Research output: Contribution to journalArticle

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abstract = "BACKGROUND: Patients with transient ischaemic attack (TIA) or minor stroke need rapid treatment of risk factors to prevent recurrent stroke. ABCD2 score or magnetic resonance diffusion-weighted brain imaging (MR DWI) may help assessment and treatment.OBJECTIVES: Is MR with DWI cost-effective in stroke prevention compared with computed tomography (CT) brain scanning in all patients, in specific subgroups or as 'one-stop' brain-carotid imaging? What is the current UK availability of services for stroke prevention?DATA SOURCES: Published literature; stroke registries, audit and randomised clinical trials; national databases; survey of UK clinical and imaging services for stroke; expert opinion.REVIEW METHODS: Systematic reviews and meta-analyses of published/unpublished data. Decision-analytic model of stroke prevention including on a 20-year time horizon including nine representative imaging scenarios.RESULTS: The pooled recurrent stroke rate after TIA (53 studies, 30,558 patients) is 5.2{\%} [95{\%} confidence interval (CI) 3.9{\%} to 5.9{\%}] by 7 days, and 6.7{\%} (5.2{\%} to 8.7{\%}) at 90 days. ABCD2 score does not identify patients with key stroke causes or identify mimics: 66{\%} of specialist-diagnosed true TIAs and 35-41{\%} of mimics had an ABCD2 score of ≥ 4; 20{\%} of true TIAs with ABCD2 score of < 4 had key risk factors. MR DWI (45 studies, 9078 patients) showed an acute ischaemic lesion in 34.3{\%} (95{\%} CI 30.5{\%} to 38.4{\%}) of TIA, 69{\%} of minor stroke patients, i.e. two-thirds of TIA patients are DWI negative. TIA mimics (16 studies, 14,542 patients) make up 40-45{\%} of patients attending clinics. UK survey (45{\%} response) showed most secondary prevention started prior to clinic, 85{\%} of primary brain imaging was same-day CT; 51-54{\%} of patients had MR, mostly additional to CT, on average 1 week later; 55{\%} omitted blood-sensitive MR sequences. Compared with 'CT scan all patients' MR was more expensive and no more 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. 'One-stop' CT/MR angiographic-plus-brain imaging was not cost-effective.LIMITATIONS: Data on sensitivity/specificity of MR in TIA/minor stroke, stroke costs, prognosis of TIA mimics and accuracy of ABCD2 score by non-specialists are sparse or absent; all analysis had substantial heterogeneity.CONCLUSIONS: Magnetic resonance with DWI is not cost-effective for secondary stroke prevention. MR was most helpful in patients presenting at > 1 week after symptoms if blood-sensitive sequences were used. ABCD2 score is unlikely to facilitate patient triage by non-stroke specialists. Rapid specialist assessment, CT brain scanning and identification of serious underlying stroke causes is the most cost-effective stroke prevention strategy.FUNDING: The National Institute for Health Research Health Technology Assessment programme.",
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author = "Joanna Wardlaw and Miriam Brazzelli and Hector Miranda and Francesca Chappell and Paul McNamee and Scotland, {Graham Stewart} and Zahid Quayyum and Duncan Martin and Kirsten Shuler and Peter Sandercock and Martin Dennis",
note = "Erratum issued September 2015 Erratum DOI: 10.3310/hta18270-c201509",
year = "2014",
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pages = "1--368, v--vi",
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TY - JOUR

T1 - An assessment of the cost-effectiveness of magnetic resonance, including diffusion-weighted imaging, in patients with transient ischaemic attack and minor stroke

T2 - a systematic review, meta-analysis and economic evaluation

AU - Wardlaw, Joanna

AU - Brazzelli, Miriam

AU - Miranda, Hector

AU - Chappell, Francesca

AU - McNamee, Paul

AU - Scotland, Graham Stewart

AU - Quayyum, Zahid

AU - Martin, Duncan

AU - Shuler, Kirsten

AU - Sandercock, Peter

AU - Dennis, Martin

N1 - Erratum issued September 2015 Erratum DOI: 10.3310/hta18270-c201509

PY - 2014/4

Y1 - 2014/4

N2 - BACKGROUND: Patients with transient ischaemic attack (TIA) or minor stroke need rapid treatment of risk factors to prevent recurrent stroke. ABCD2 score or magnetic resonance diffusion-weighted brain imaging (MR DWI) may help assessment and treatment.OBJECTIVES: Is MR with DWI cost-effective in stroke prevention compared with computed tomography (CT) brain scanning in all patients, in specific subgroups or as 'one-stop' brain-carotid imaging? What is the current UK availability of services for stroke prevention?DATA SOURCES: Published literature; stroke registries, audit and randomised clinical trials; national databases; survey of UK clinical and imaging services for stroke; expert opinion.REVIEW METHODS: Systematic reviews and meta-analyses of published/unpublished data. Decision-analytic model of stroke prevention including on a 20-year time horizon including nine representative imaging scenarios.RESULTS: The pooled recurrent stroke rate after TIA (53 studies, 30,558 patients) is 5.2% [95% confidence interval (CI) 3.9% to 5.9%] by 7 days, and 6.7% (5.2% to 8.7%) at 90 days. ABCD2 score does not identify patients with key stroke causes or identify mimics: 66% of specialist-diagnosed true TIAs and 35-41% of mimics had an ABCD2 score of ≥ 4; 20% of true TIAs with ABCD2 score of < 4 had key risk factors. MR DWI (45 studies, 9078 patients) showed an acute ischaemic lesion in 34.3% (95% CI 30.5% to 38.4%) of TIA, 69% of minor stroke patients, i.e. two-thirds of TIA patients are DWI negative. TIA mimics (16 studies, 14,542 patients) make up 40-45% of patients attending clinics. UK survey (45% response) showed most secondary prevention started prior to clinic, 85% of primary brain imaging was same-day CT; 51-54% of patients had MR, mostly additional to CT, on average 1 week later; 55% omitted blood-sensitive MR sequences. Compared with 'CT scan all patients' MR was more expensive and no more 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. 'One-stop' CT/MR angiographic-plus-brain imaging was not cost-effective.LIMITATIONS: Data on sensitivity/specificity of MR in TIA/minor stroke, stroke costs, prognosis of TIA mimics and accuracy of ABCD2 score by non-specialists are sparse or absent; all analysis had substantial heterogeneity.CONCLUSIONS: Magnetic resonance with DWI is not cost-effective for secondary stroke prevention. MR was most helpful in patients presenting at > 1 week after symptoms if blood-sensitive sequences were used. ABCD2 score is unlikely to facilitate patient triage by non-stroke specialists. Rapid specialist assessment, CT brain scanning and identification of serious underlying stroke causes is the most cost-effective stroke prevention strategy.FUNDING: The National Institute for Health Research Health Technology Assessment programme.

AB - BACKGROUND: Patients with transient ischaemic attack (TIA) or minor stroke need rapid treatment of risk factors to prevent recurrent stroke. ABCD2 score or magnetic resonance diffusion-weighted brain imaging (MR DWI) may help assessment and treatment.OBJECTIVES: Is MR with DWI cost-effective in stroke prevention compared with computed tomography (CT) brain scanning in all patients, in specific subgroups or as 'one-stop' brain-carotid imaging? What is the current UK availability of services for stroke prevention?DATA SOURCES: Published literature; stroke registries, audit and randomised clinical trials; national databases; survey of UK clinical and imaging services for stroke; expert opinion.REVIEW METHODS: Systematic reviews and meta-analyses of published/unpublished data. Decision-analytic model of stroke prevention including on a 20-year time horizon including nine representative imaging scenarios.RESULTS: The pooled recurrent stroke rate after TIA (53 studies, 30,558 patients) is 5.2% [95% confidence interval (CI) 3.9% to 5.9%] by 7 days, and 6.7% (5.2% to 8.7%) at 90 days. ABCD2 score does not identify patients with key stroke causes or identify mimics: 66% of specialist-diagnosed true TIAs and 35-41% of mimics had an ABCD2 score of ≥ 4; 20% of true TIAs with ABCD2 score of < 4 had key risk factors. MR DWI (45 studies, 9078 patients) showed an acute ischaemic lesion in 34.3% (95% CI 30.5% to 38.4%) of TIA, 69% of minor stroke patients, i.e. two-thirds of TIA patients are DWI negative. TIA mimics (16 studies, 14,542 patients) make up 40-45% of patients attending clinics. UK survey (45% response) showed most secondary prevention started prior to clinic, 85% of primary brain imaging was same-day CT; 51-54% of patients had MR, mostly additional to CT, on average 1 week later; 55% omitted blood-sensitive MR sequences. Compared with 'CT scan all patients' MR was more expensive and no more 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. 'One-stop' CT/MR angiographic-plus-brain imaging was not cost-effective.LIMITATIONS: Data on sensitivity/specificity of MR in TIA/minor stroke, stroke costs, prognosis of TIA mimics and accuracy of ABCD2 score by non-specialists are sparse or absent; all analysis had substantial heterogeneity.CONCLUSIONS: Magnetic resonance with DWI is not cost-effective for secondary stroke prevention. MR was most helpful in patients presenting at > 1 week after symptoms if blood-sensitive sequences were used. ABCD2 score is unlikely to facilitate patient triage by non-stroke specialists. Rapid specialist assessment, CT brain scanning and identification of serious underlying stroke causes is the most cost-effective stroke prevention strategy.FUNDING: The National Institute for Health Research Health Technology Assessment programme.

KW - Aged

KW - Cost-Benefit Analysis

KW - Diffusion Magnetic Resonance Imaging

KW - Female

KW - Humans

KW - Ischemic Attack, Transient

KW - Male

KW - Middle Aged

KW - Neuroimaging

KW - Stroke

KW - Tomography, X-Ray Computed

U2 - 10.3310/hta18270

DO - 10.3310/hta18270

M3 - Article

VL - 18

SP - 1-368, v-vi

JO - Health Technology Assessment

JF - Health Technology Assessment

SN - 1366-5278

IS - 27

ER -