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When has service provision for transient ischaemic attack improved enough? A discrete event simulation economic modelling study
  1. Pelham Barton1,
  2. James P Sheppard2,
  3. Cristina M Penaloza-Ramos1,
  4. Sue Jowett1,
  5. Gary A Ford3,
  6. Daniel Lasserson4,
  7. Jonathan Mant5,
  8. Ruth M Mellor6,
  9. Tom Quinn7,
  10. Peter M Rothwell8,
  11. David Sandler9,
  12. Don Sims10,
  13. Richard J McManus2
  14. on behalf of the BBC CLAHRC investigators
  1. 1 Health Economics Unit, University of Birmingham, Birmingham, UK
  2. 2 Nuffield Department of Primary Care Health Sciences, NIHR School for Primary Care Research, University of Oxford, Oxford, UK
  3. 3 Oxford Academic Health Science Network, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
  4. 4 Nuffield Department of Medicine, University of Oxford, Oxford, UK
  5. 5 Primary Care Unit, University of Cambridge, Cambridge, UK
  6. 6 Department of Public Health, NHS Lanarkshire, Bothwell, UK
  7. 7 Centre for Health and Social Care Research, Faculty of Health, Social Care and Education, St George’s University of London, Kingston University, London, UK
  8. 8 Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
  9. 9 Geriatric Medicine, Heart of England NHS Foundation Trust, Birmingham, UK
  10. 10 Stroke Medicine, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
  1. Correspondence to Dr James P Sheppard; james.sheppard{at}


Objectives The aim of this study was to examine the impact of transient ischaemic attack (TIA) service modification in two hospitals on costs and clinical outcomes.

Design Discrete event simulation model using data from routine electronic health records from 2011.

Participants Patients with suspected TIA were followed from symptom onset to presentation, referral to specialist clinics, treatment and subsequent stroke.

Interventions Included existing versus previous (less same day clinics) and hypothetical service reconfiguration (7-day service with less availability of clinics per day).

Outcome measures The primary outcome of the model was the prevalence of major stroke after TIA. Secondary outcomes included service costs (including those of treating subsequent stroke) and time to treatment and attainment of national targets for service provision (proportion of high-risk patients (according to ABCD2 score) seen within 24 hours).

Results The estimated costs of previous service provision for 490 patients (aged 74±12 years, 48.9% female and 23.6% high risk) per year at each site were £340 000 and £368 000, respectively. This resulted in 31% of high-risk patients seen within 24 hours of referral (47/150) with a median time from referral to clinic attendance/treatment of 1.15 days (IQR 0.93–2.88). The costs associated with the existing and hypothetical services decreased by £5000 at one site and increased £21 000 at the other site. Target attainment was improved to 79% (118/150). However, the median time to clinic attendance was only reduced to 0.85 days (IQR 0.17–0.99) and thus no appreciable impact on the modelled incidence of major stroke was observed (10.7 per year, 99% CI 10.5 to 10.9 (previous service) vs 10.6 per year, 99% CI 10.4 to 10.8 (existing service)).

Conclusions Reconfiguration of services for TIA is effective at increasing target attainment, but in services which are already working efficiently (treating patients within 1–2 days), it has little estimated impact on clinical outcomes and increased investment may not be worthwhile.

  • economic modelling
  • stroke
  • secondary care
  • secondary prevention
  • health services

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  • Contributors RJMcM, JM, SJ and PB had the original idea and gained the funding for the project. PB undertook the economic analyses. JPS and RMM were responsible for the data collection and JPS wrote the first draft of the manuscript with RJMcM and PB. All authors contributed to protocol development, refined the manuscript and approved the final version. RJMcM is the guarantor.

  • Funding This work was supported by the National Institute for Health Research (NIHR) as part of the Collaborations for Leadership in Applied Health Research and Care (CLAHRC) programme for Birmingham and Black Country. JPS held a Medical Research Council (MRC grant number MR/K022032/1) Strategic Skills Postdoctoral Fellowship and is now funded by the NIHR Oxford CLARHC. RJMcM holds an NIHR Professorship.

  • Competing interests None declared.

  • Ethics approval Approval for this project was obtained from the National Research Ethics Service (NRES) Committee, London – Queen Square (reference; 09/H0716/71).

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement The datasets analysed during the current study are available from the corresponding author on reasonable request.

  • Collaborators Birmingham and Black Country Collaborations for Leadership in Applied Health Research and Care investigators include: Peter Carr, Heart of England NHS Foundation Trust; Sheila Greenfield, Primary Care Clinical Sciences, University of Birmingham; Brin Helliwell, Lay member of Steering Group, Christina Nand, Lay member of Steering Group; Norman Phillips, Lay member of Steering Group; Rob Scott, Birmingham and Midland Eye Centre; Satinder Singh, Primary Care Clinical Sciences, University of Birmingham; Matthew Ward, West Midlands Ambulance Service NHS Trust.

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