Editorials

Hyperacute stroke care and NHS England’s business plan

BMJ 2014; 348 doi: https://doi.org/10.1136/bmj.g3049 (Published 02 May 2014) Cite this as: BMJ 2014;348:g3049
  1. Thomas Monks, research fellow1,
  2. Martin Pitt, associate professor1,
  3. Ken Stein, professor of public health1,
  4. Martin A James, consultant stroke physician2
  1. 1National Institute for Health Research Collaboration in Leadership and Applied Health Research and Care, University of Exeter Medical School, University of Exeter, Exeter EX2 4SG, UK
  2. 2Royal Devon and Exeter Hospital, Exeter, UK
  1. t.monks{at}exeter.ac.uk

Computer simulation, coupled with high quality data, can help in decision making

NHS England’s refreshed business plan identifies the reconfiguration of hyperacute stroke services as a priority. NHS England aims to develop the case for major reconfigurations in two further geographical locations by April 2015.1 This priority follows the centralisation of London’s acute stoke care in 2010, in which 30 local hospitals receiving stroke patients were reduced to eight hyperacute stroke units, each within a maximum ambulance travel time of 30 minutes. In a before and after study,2 the thrombolysis rate increased from 5% to 12%, the survival rate increased from 87.2% to 88.7%, and centralisation achieved an estimated 90 day cost saving of more than £5m (€6.1; $8.4m) a year.

Improvements have continued, with 2013 audit data for London reporting a thrombolysis rate of 17% and median door to needle times ranging from 29 to 48 minutes compared with an English average of 12% and median 59 minutes, respectively.3 Given London’s success, an important question arises for many NHS commissioners: would such a reconfiguration be just as effective outside the major conurbations?

Central to this question is the exquisitely time sensitive nature of the benefit from thrombolysis for acute ischaemic stroke. The time effect is such that the number needed to treat to achieve one additional favourable outcome (a modified Rankin score of 0 or 1 indicating no or minimal disability at 90 days) effectively doubles with each 90 minute interval from the onset of symptoms, and beyond four and a half hours the harms outweigh the benefits.4 The most recent randomised trial of alteplase in ischaemic stroke, the third international stroke trial, has further emphasised the critical time dependency of stroke thrombolysis.5 To boost treatment rates and improve outcomes hospitals have sought to minimise the time taken to treat a patient after ambulance arrival, and the example of London is one of a handful of international cities where door to needle times have been dramatically reduced.6

So how might stroke services in dispersed rural areas with much longer ambulance travel times confer the same benefits to patients with stroke as in the major conurbations? One promise of larger centralised units with higher patient volumes is, among other things, that they will shorten door to needle time, resulting in improved outcomes. However, implementing a centralised model in rural areas is likely to increase ambulance travel times, particularly for those patients who live near to a closed unit, thereby jeopardising the benefits of centralisation. Understanding this trade-off and the benefits and risks of reconfiguration in terms of outcomes is a key issue for evidence based commissioning and one of acute interest to the populations affected. Put simply, there is a need for robust evidence that centralisation will be as effective in a rural environment as in an urban one.

Intelligent redesign

For commissioners facing decisions about how best to reorganise stroke care, help is at hand. The consequences of reconfiguration can be analysed: computer simulations (some of which we have contributed to) can be used to estimate the impact of changes in hyperacute service delivery on treatment rates and disability outcomes.7 8 9 10 11 These approaches are ideally suited to urgent care reconfigurations, especially where, unlike in London, travel times may be a substantial source of delays to treatment.

Simulations can incorporate many factors that simple travel time analyses cannot: predictions of patient outcomes; longer travel times during peak hours; queuing effects in busy emergency and radiology departments with competing priorities; stroke physician availability (either on site or remotely by telemedicine); or multiple ambulance and provider configurations. These factors can be combined in a detailed and risk-free analysis of the gainers and losers from reconfiguration. How many patients stand to gain and how many will lose out, and with what probability? Or, how short must door to needle times be to preserve or increase the benefits of thrombolysis in a centralised stroke network? Decisions on reconfiguration in rural areas cannot be made with confidence without this level of analysis.

Sceptics of mathematical modelling often object that models are only as good as the data they are built from. So it’s reassuring that high quality data in acute stroke are now available. The Sentinel Stroke National Audit programme (SSNAP), which began in January 2013, has collected data from more than 80 000 patients with stroke admitted to more than 160 hospitals in England, Wales, and Northern Ireland. SSNAP represents a powerful opportunity to use large scale clinical data for quality improvement and is well suited to modelling hyperacute stroke care, coupled to high quality data on response and travel times available from ambulance services. This provides a timely opportunity to drive the intelligent redesign of hyperacute stroke care in the United Kingdom in conjunction with the other urgent care priorities outlined in NHS England’s review of urgent and emergency care.12

The priority given to delivering hyperacute stroke reconfigurations in NHS England’s business plan means that clinical commissioning groups in England will face difficult decisions about how best to reprovision acute stroke care over the next few years. However, accepting centralisation or dismissing it on the basis of little or no quantitative analysis would be to fail to understand the important trade-offs and gains in stroke disability that would result. We believe it is important for decisions on the configuration of stroke services to be taken explicitly, after careful consideration of all the available evidence. Computer simulation is able to inject some robust analysis into what will be a complex debate.

Notes

Cite this as: BMJ 2014;348:g3049

Footnotes

  • Competing interests: We have read and understood BMJ policy on declaration of interests and declare the following interests: MAJ has received fees as an advisory board member or speaker for Boehringer Ingelheim, Bristol-Myers-Squibb, Bayer, Pfizer, Roche, and GE.

  • Provenance and peer review: Commissioned; not externally peer reviewed.

References

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