Final project report · 2020. 5. 20. · Final project report . Summary . A one-year AHSN-sponsored collaborative project with hyperacute stroke centres in the South West ... The

South West Cardiovascular Strategic Clinical Network

South West Cardiovascular Strategic Clinical Network

Achieving step-change in the emergency stroke pathway across the SW AHSN

Final project report

Summary

A one-year AHSN-sponsored collaborative project with hyperacute stroke centres in the South West

Peninsula involved computer simulation of the emergency stroke pathway and a bespoke

implementation plan to increase the uptake of thrombolysis for acute ischaemic stroke

The project identified that centres with historically low and slow rates of thrombolysis are capable

of delivering treatment at rates in excess of large urban hyperacute units. Analysis identified critical

factors in thrombolysis processes and practice which could increase both the proportion of patients

receiving treatment and the speed with which treatment is delivered

Realistic and achievable changes to the hyperacute stroke pathway in SW Centres could triple the

benefit from thrombolysis for acute ischaemic stroke, reduce stroke-related disability and save up to

£8.7M over 5 years

Background and Aims

Thrombolysis for ischaemic stroke reduces disability and improves quality of life after a stroke – in so doing

reducing the burden on carers and the long-term costs to health and social services. Thrombolysis with

alteplase is supported by high quality RCT evidence and by a range of national (NICE) and international

guidance, but worldwide adoption of the treatment has been highly variable since the publication of the first

RCT 20 years ago. The benefits of thrombolysis are critically time-sensitive – the earlier treatment is

received, the greater the chance of recovery with minimal or no disability.

Major service redesign in the London area involving the development of a small number of hyperacute

stroke centres has increased thrombolysis treatment rates from less than 5% to between 14-25%, among the

highest in any metropolitan area worldwide. With consequent reductions in long term disability and

resource use, this provides convincing evidence of cost-effectiveness to support service redesign. Work

from the national stroke audit SSNAP indicates that for every patient thrombolysed, net healthcare costs are

reduced by £4,100 over the next 5 years (https://www.strokeaudit.org/Health-Economics.aspx).

PenCLAHRC’s precursor work on the emergency stroke pathway at the Royal Devon and Exeter Hospital

(RD&E) has yielded a thrombolysis rate at least as good as that of several of the London hyperacute centres,

achieving 17% on completion of a quality improvement project in 2013, a rate that has since been

maintained. Yet many other SW centres continue to have lower rates, some as low as 3-4%, with long door-

to-needle times further diminishing the potential to benefit even when treated.

The SW AHSN-funded ‘Stroke Pathways’ project had the overall aim to reduce stroke-related disability and

costs by speeding up the real-world implementation of the clinical evidence for thrombolysis in acute stroke.

The project objectives were:

https://www.strokeaudit.org/Health-Economics.aspx

1. To identify process changes within hospitals that could increase the delivery of thrombolysis treatment

in appropriate cases, and to quantify the disability benefit to patients from changes to the emergency

stroke pathway;

2. To identify and address barriers to implementation within emergency stroke centres.

The project was an innovative collaboration between the SW AHSN, the PenCHORD Operational Research

group within SW Peninsula CLAHRC, the SW Cardiovascular Strategic Clinical Network (CV SCN) and the

following trusts: Derriford Hospital, Torbay Hospital, North Devon District Hospital, Royal Cornwall Hospital,

Musgrove Park Hospital Taunton, Yeovil District Hospital and the South Western Ambulance Service.

Methods

The year-long project was supervised by a joint steering group which first met in February 2015. An

experienced Stroke Quality Improvement Manager (SQIM), Carol Massey, was appointed on a one-year

secondment from NEW Devon CCG to work with participating trusts in developing bespoke improvements in

their hyperacute stroke pathway. Carol Massey worked in close collaboration with Dr Mike Allen and Kerry

Pearn, the academic operational research modellers with PenCHORD.

Simulation models of the hyperacute stroke pathway

In each acute stroke centre the SQIM and modellers used the centre’s own national audit (SSNAP) individual

patient data to construct a discrete event simulation of their hyperacute stroke pathway, taking into account

local aspects of structure and process such as staffing levels at different times of day. This analysis identified

three critical factors in determining a centre’s overall thrombolysis rate:

the proportion of patients with a known time of stroke onset;

the time from arrival in hospital to thrombolysis i.e. door-to-needle time;

the proportion of patients who arrive with 30 minutes remaining in the licence window who are

ultimately thrombolysed. This indicates the centre’s willingness to consider thrombolysis since, in

many cases, clinical judgement determines whether a person’s stroke is ‘too mild’ or ‘too severe’ for

thrombolysis to be indicated.

The simulations were manipulated to explore the potential effects of different organisation of the

hyperacute pathway, testing ‘what if’s in a range of scenarios and exploring the resultant disability benefits

from changes in the centre’s use of thrombolysis. An important part of this approach was to consider what

the influence might be if the performance of another site, or the national average, for important factors

were replicated at any given site.

Identifying barriers and facilitators to change

In addition to the quantitative findings generated by simulation modelling, the process also identified

barriers and facilitators for change within a trust based on the configuration of services and the various

stakeholders within the organisation. The SQIM supported providers in identifying and working towards the

step changes illustrated by the simulation and sanctioned by Trust managers and clinicians.

Outputs

Each centre was provided with an individualised report identifying the key changes in their thrombolysis

practice and processes that would result in the greatest disability gain. These varied by centre, illustrating

the need for a bespoke solution rather than a ‘one size fits all’ approach. Overall, it was possible to

demonstrate to centres that, despite the received wisdom that prevailed regarding late presentations or

local differences in the eligible population, overall thrombolysis rates of 15-20% are achievable across the

SW AHSN area – see Table 1 for the summary results of the simulation. All centres demonstrated the

potential for a 2-4-fold increase in the numbers of patients with little or no disability after stroke through

readily achievable changes to the hyperacute stroke pathway.

Table 1. Overall scenario results for participating centres – thrombolysis rates as a proportion of all strokes (upper panel), and the

predicted benefit in terms of patients with little or no disability (modified Rankin Scale [MRS] or 0-1)(lower panel.

The impact of changes to the pathway was different for each hospital: improvements needed to be targeted

initially at the factors that would drive the greatest improvement in clinical outcome at each centre. Figure

1 shows a worked example for North Devon District Hospital, Barnstaple.

Figure 1: Potential gains in thrombolysis rate and disability benefit from changes to thrombolysis practice in North Devon District

Hospital

Across the whole AHSN area, these changes offer the prospect of a two- to three-fold increase in the number

of patients who are left with no disability after stroke, from the present 30/year to over 80/year, based on

realistic, achievable changes. The overall proportion of patients treated could be increased from 8.6% at

Exeter Torbay Plymouth Truro Barnstaple Yeovil TauntonBase case: Current perfomrance for each hospital 11.9 7.0 8.2 8.3 6.7 11.7 7.3Scenario 1: Speed: 22.5 mins each for arrival to scan and scan to thrombolysis 17.0 11.2 10.7 8.9 8.3 15.7 8.4Scenario 2: Known stroke onset 74.4% 14.1 8.7 10.9 14.0 11.5 11.9 10.0Scenario 3: Thrombolysis rate 49% for those with 30 min left 11.3 9.5 12.0 11.1 10.5 15.6 13.2Scenario 4: Licence window for age 80+ extended to 270 mins 14.6 8.9 10.3 9.4 7.5 15.2 8.8Scenario 5: Scenarios 1+2 20.3 13.8 14.4 15.2 14.4 16.3 11.7Scenario 6: Scenarios 1+3 16.5 15.7 15.8 12.2 13.4 20.3 15.3Scenario 7: Scenarios 2+3 13.4 11.9 16.2 18.8 18.0 15.5 18.1Scenario 8: Scenarios 1+2+3 19.7 19.3 21.2 20.8 22.8 21.1 21.0Scenario 9: Scenarios 1+2+3+4 22.3 21.7 23.2 23.2 24.4 23.7 23.2

Exeter Torbay Plymouth Truro Barnstaple Yeovil TauntonBase case: Current performance for each hospital 0.97 0.60 0.63 0.68 0.48 1.09 0.70Scenario 1: Speed: 22.5 mins each for arrival to scan and scan to thrombolysis 1.55 1.10 0.99 0.82 0.74 1.56 0.86Scenario 2: Known stroke onset 74.4% 1.12 0.76 0.85 1.19 0.91 1.14 0.87Scenario 3: Thrombolysis rate 49% for those with 30 min left 0.93 0.82 0.93 0.96 0.85 1.51 1.18Scenario 4: Licence window for age 80+ extended to 270 mins 1.15 0.72 0.78 0.80 0.55 1.32 0.79Scenario 5: Scenarios 1+2 1.85 1.32 1.31 1.39 1.42 1.64 1.14Scenario 6: Scenarios 1+3 1.51 1.51 1.45 1.14 1.31 1.83 1.48Scenario 7: Scenarios 2+3 1.13 0.99 1.22 1.63 1.42 1.46 1.54Scenario 8: Scenarios 1+2+3 1.80 1.88 1.93 1.94 2.09 1.96 1.93Scenario 9: Scenarios 1+2+3+4 2.00 2.01 2.07 2.09 2.21 2.29 2.04


Predicted benefit (Additional MRS0-1 patients for 100 admitted stroke patients)

Thrombolysis useage (% all patients)

Predicted benefit (additional patients MRS0-1)

Exeter Torbay Plymouth Truro Barnstaple Yeovil TauntonBase case: Current perfomrance for each hospital 11.9 7.0 8.2 8.3 6.7 11.7 7.3Scenario 1: Speed: 22.5 mins each for arrival to scan and scan to thrombolysis 17.0 11.2 10.7 8.9 8.3 15.7 8.4Scenario 2: Known stroke onset 74.4% 14.1 8.7 10.9 14.0 11.5 11.9 10.0Scenario 3: Thrombolysis rate 49% for those with 30 min left 11.3 9.5 12.0 11.1 10.5 15.6 13.2Scenario 4: Licence window for age 80+ extended to 270 mins 14.6 8.9 10.3 9.4 7.5 15.2 8.8Scenario 5: Scenarios 1+2 20.3 13.8 14.4 15.2 14.4 16.3 11.7Scenario 6: Scenarios 1+3 16.5 15.7 15.8 12.2 13.4 20.3 15.3Scenario 7: Scenarios 2+3 13.4 11.9 16.2 18.8 18.0 15.5 18.1Scenario 8: Scenarios 1+2+3 19.7 19.3 21.2 20.8 22.8 21.1 21.0Scenario 9: Scenarios 1+2+3+4 22.3 21.7 23.2 23.2 24.4 23.7 23.2



Predicted benefit (Additional MRS0-1 patients for 100 admitted stroke patients)

Thrombolysis useage (% all patients)

Predicted benefit (additional patients MRS0-1)

present to 20.8% without any changes to the licence window for thrombolysis (Scenario 8 below) – an

increase of 486 patients treated per year, resulting in net healthcare savings of up to £8.7M over 5 years.

Figure 2: Number of patients per year in the SW AHSN area who leave hospital disability-free due to use of thrombolysis

Centres identified their own key actions for implementation, and were supported in deriving and

implementing their action plan by the SQIM. The extent to which the action plans were implemented by

project closure varied according to the point in the year when their participation began. However, key

actions included, for example, giving greater priority to efforts to identify a known time of stroke onset to

match the national average, a reappraisal of the clinical rationale for treating patients with mild or severe

stroke and the introduction of stroke nurse practitioners with the express purpose of reducing door-to-

needle time and harmonising thrombolysis practice and patient selection.

At an end-of-project event ‘Improving the Delivery of Hyperacute Stroke Care’ at Exeter Racecourse on July

21, 2016, the overall project results were presented, with centres sharing their learning from participation

and reporting on progress with their implementation plans. Changes in door-to-needle times, known onset

times and overall thrombolysis rate will be monitored by the SW CV SCN through its regional reports from

the national prospective stroke audit, SSNAP, to understand the extent to which centres prove able to

implement and sustain the practice changes identified through participation in the ‘Stroke Pathways’

project. PenCLAHRC will develop a range of academic outputs from the project, reflecting progress and

learning to date and the analysis of prospective data, highlighting the collaboration with the SW AHSN in

achieving real service impact. A related project, jointly funded by the SW AHSN and PenCLAHRC (‘ASPIC’), is

studying the barriers and facilitators to change in sites which participated in the Stroke Pathways Project,

seeking to derive guidance and tools for implementation that can be more widely applied among our NHS

partners in the South West.

Report compiled by Mike Allen, Carol Massey, Ken Stein and Martin James

20 October 2016

Documents

Final project report · 2020. 5. 20. · Final project report . Summary . A one-year AHSN-sponsored collaborative project with hyperacute stroke centres in the South West ... The