Management of patients with stroke or TIA: assessment, investigation, immediate management and secondary prevention

Transcription

1 Management of patients with stroke or TIA: assessment, investigation, immediate management and secondary prevention A clinical and resource impact assessment May 2009

2 Quality Improvement Scotland 2009 Quality Improvement Scotland ( QIS) consents to the photocopying, electronic reproduction by uploading or downloading from the website, retransmission, or other copying of this report for the purpose of implementation in Scotland and educational and not-for-profit purposes. No reproduction by or for commercial organisations is permitted without the express written permission of QIS.

3 CONTENTS 1 EXECUTIVE SUMMARY INTRODUCTION Objective Key recommendations Document overview BACKGROUND AND METHODOLOGY Introduction Methodology to estimate clinical benefit Methodology to estimate resources required/associated costs and savings Methodology to estimate cost of resources and associated savings Limitations SCOTTISH STROKE EPIDEMIOLOGY Introduction Incidence of a first hospital admission as a result of stroke or TIA TIMELY THROMBOLYSIS Background Patient group Clinical benefit and associated resource savings Resource requirements Costs Sensitivity analysis Analyses by board TIMELY CAROTID IMAGING AND CAROTID ENDARTERECTOMY Background Patient group Clinical benefit and associated resource savings Resource requirements Costs Sensitivity analysis Analyses by board TIMELY CT DIAGNOSTICS Background Patient group Clinical benefits Resources Costs Sensitivity analysis... 44

4 8 REFERENCES APPENDICES Appendix 1 Key recommendations Appendix 2 Acknowledgements Appendix 3 Resource impact assessment process Appendix 4.1 ICD-10 codes for stroke or TIA Appendix 4.2 ICD-10 codes for other cerebrovascular diseases Appendix 5.1 Incidence of first ever hospital admission for stroke and TIA for year ending 31 March Appendix 5.2 Survival rates for stroke and TIA after a first ever hospital admission for year ending 31 March Appendix 5.3 Re-admission rates for stroke and TIA after a first ever hospital admission for year ending 31 March Appendix 5.4 Prior admission of patients who had a first ever admittance for stroke or TIA for year ending 31 March Appendix 5.5 Incidence of stroke and TIA resulting in a first ever hospital admission by board for year ending 31 March Appendix 5.6 Predicted mortality for patients with first admission of ischaemic stroke for year ending 31 March Appendix 5.7 Predicted mortality and disability for patients with first admission of ischaemic stroke for year ending 31 March Appendix 6.1 Estimated first hospital admissions for stroke or TIA Appendix 6.2 Estimated survival rates for patients following a first admission to hospital for stroke or TIA Appendix 6.3 Estimated re-admission rates for patients following a first admission to hospital for stroke or TIA Appendix 6.4 Estimated prior admission rates for patients later admitted for stroke or TIA for the first time Appendix 6.5 Estimated admission rates for patients who have attended a neurovascular outpatient clinic Appendix 7.1 Costs for the Scottish Ambulance Service Appendix 7.2 Costs for attendance at an A&E department Appendix 7.3 Costs per event for CT, MRI and ultrasound diagnostics Appendix 7.4 Costs for a stroke consultant outpatient attendance Appendix 7.5 Costs for a consultant vascular surgeon outpatient attendance Appendix 7.6 Mean variable cost per day (excluding overheads and theatre costs) in a surgical ward Appendix 7.7 Mean variable cost per day (excluding overheads and theatre costs) in a general medical ward Appendix 7.8 Costs per hour for theatre time inclusive of overheads, staff costs and consumables... 72

5 Appendix 7.9 Costs by function in Greater Glasgow and Clyde LIST OF TABLES Table 1-1 Clinical benefits measured as the number of bed days saved... 4 Table 1-2 Additional costs required to implement key recommendations... 6 Table 1-3 budgetary impact for Scotland and board... 7 Table 3-1 Gross salary costs for non-consulting staff Table 3-2 Gross salary costs for consulting staff Table 3-3 Consolidated surgical costs for carotid endarterectomy Table 4-1 Re-admission rates Table 4-2 Annual re-admission rates estimated from first ever hospital admissions 21 Table 4-3 Classification of the subtypes of cerebral infarcts Table 4-4 Extending OCSP model of infarction subtypes to age groups 23 Table 5-1 Clinical benefits of additional thrombolytic therapy Table 5-2 Additional costs to deliver thrombolytic therapy Table 5-3 Additional costs if patients not directed to hospitals with CT scanners Table 5-4 Additional costs to deliver thrombolytic therapy Table 5-5 Anticipated patients by board Table 5-6 Additional benefit from timely thrombolysis by board Table 5-7 Additional costs from timely thrombolysis by board Table 5-8 Sensitivity analysis: SAS unable to deliver patients to specified Table 6-1 Calculation to estimate number of patients eligible for surgery Table 6-2 Patients who are potential candidates for carotid endarterectomy Table 6-3 Estimated clinical benefit from timely carotid endarterectomy Table 6-4 Estimated additional cost to achieve timely carotid endarterectomy Table 6-5 Sensitivity analyses of higher costs incurred if carotid Doppler required. 40 Table 7-1 Patient groups requiring CT scanning facilities Table 7-2 Operational CT scanning hours per week in Scottish hospitals Table 7-3 Costs to provide capacity to scan 24,300 people with stroke symptoms. 44

6 1 EXECUTIVE SUMMARY In their recent report, Reducing Brain Damage: Faster access to better stroke care 1, the National Audit Office stated that in England and Wales, stroke costs the and the economy approximately 7 billion a year. Of this sum, 2.8 billion is estimated to be in direct costs to the, 2.4 billion of informal care costs borne by the patients family and other carers, with a further 1.8 billion being lost productivity and disability income for those under the age of 65 who are unable to work as a result of their condition. Translating these numbers to Scotland suggests that the cost to the Scottish economy as a result of stroke is in the region of some 700 million. Whilst stroke is primarily associated with age and ageing, it is important to note that the number of patients under the age of 65 who are being admitted to Scottish hospitals due to stroke is increasing. This group now represents 26.5% of all stroke admissions; up 32.5% from the 20.0% of admissions reported in 2000 as part of the Scottish Borders Stroke Study 2. Moreover, while the reported incidence of stroke has decreased marginally over the last 10, this trend may not continue because of the demographics. In the next 10, one of the largest deciles, the age group, or the baby boomers, will progressively move into the next of the higher risk stroke age groups. The objective of this clinical and resource impact assessment is to facilitate more rapid implementation of the key recommendations in SIGN Guideline 108 Management of patients with stroke or TIA: assessment, investigation, immediate management and secondary prevention 3. The report provides each board with an estimate of the resources and costs required to implement the key recommendations, together with the associated clinical benefits, including potential cost savings. The guideline development group judged 15 recommendations to be clinically very important and should be prioritised for implementation. Following discussion with members of the group it was agreed that eight recommendations would not change current practice and therefore would not have a material impact on current resource use. These have been excluded from further analysis. A short explanation of each recommendation including commentary for those that have been excluded is provided in Appendix 1. Seven recommendations were judged to be clinically important and to require significant resources on implementation. The associated clinical benefits, resources and costs to implement these key recommendations are estimated in this report. These have been grouped into two headings; timely thrombolysis and timely carotid imaging and carotid endarterectomy. Implementing these two interventions are the key challenges for boards. The individual recommendations for each intervention are: 1

7 Recommendations for timely thrombolysis Emergency medical services should be redesigned to facilitate rapid access to specialist stroke services. Stroke patients requiring admission to hospital should be admitted to a stroke unit staffed by a co-ordinated multidisciplinary team with a special interest in stroke care. All patients with suspected stroke should have brain imaging immediately on presentation. Patients admitted with stroke within 4.5 hours of definite onset of symptoms, who are considered suitable, should be treated with 0.9 mg/kg (up to maximum 90 mg) intravenous recombinant tissue plasminogen activator (rt-pa). Recommendations for timely carotid imaging and carotid endarterectomy All patients with non-disabling acute stroke syndrome/transient ischaemic attack (TIA) in the carotid territory who are potential candidates for carotid surgery should have carotid imaging. All patients with carotid artery territory stroke (without severe disability, modified Rankin Scale [mrs] 2) or TIA should be considered for carotid endarterectomy as soon as possible after the index event. Carotid endarterectomy (on the internal carotid artery ipsilateral to the cerebrovascular event) should be considered in all: - male patients with a carotid artery stenosis of 50 99% (by NASCET method) - female patients with a carotid artery stenosis of 70 99%. For all patients, carotid endarterectomy should be performed as soon as the patient is stable and fit for surgery, ideally within 2 weeks of the initial event. Implementing both interventions requires the use of radiological diagnostics to assist in the primary determination of specific stroke type. The analysis contained in Section 7 on timely computed tomography (CT) diagnostics suggests approximately 24,300 CT scans will be required annually for all patients with potential strokes, to include those scanned immediately after thrombolysis. The resources and costs to manage a service to deliver these are also discussed. The methodology used to develop this report adopts proven processes and principles 4-7. Members of the guideline development group and other experts have provided advice and participated in peer review. The draft findings were presented to representatives from Dumfries & Galloway, Ayrshire & Arran, Lanarkshire and Greater Glasgow and Clyde. Due to time constraints, it was not possible to visit all boards in Scotland. However, the remaining boards were provided with drafts of all the underlying analyses for comment and feedback. The boards visited represent the 2

8 varying spatial diversity of all boards, namely those that have one major hospital, two major hospitals, three major hospitals and multiple sites. The feedback from the visits has been adapted for the remaining boards. The information contained within this report at a national level represents the clinical, resource and budget impact consolidation of each of the individual mainland boards, with the boards of Orkney, Shetland and Western Isles combined into a single entity, the island boards. The epidemiological variations that exist between the boards in Scotland have been taken into account in the preparation of this work through extensive epidemiological modelling covering the last 3. Estimated clinical benefits of implementing the key recommendations Implementing SIGN 108 is forecast to require: 810 more patients receiving thrombolysis, compared to the current number of 205, and 608 more patients receiving a carotid endarterectomy, and improving the timeliness of the current 552 procedures such that these are delivered within 14 days from event. Diagnosing and managing these patients will require radiology departments to provide CT scanning and other imaging services for approximately 24,300 patients per year. The clinical benefits forecast following these interventions are estimated to be: 82 patients making a full recovery and 364 having an improved outcome following thrombolysis, and 217 recurrent strokes avoided from timely carotid endarterectomy. The associated bed days saved are estimated at 10,611, of which 4,752 are achieved by timely thrombolysis and 5,859 from timely carotid endarterectomy. The financial benefits are estimated at 2.94 million. This is calculated by applying a weighted average variable cost for Scotland (excluding overheads) of 277 per bed day. Table 1 1 gives the benefits by board for each intervention. No account has been taken of the savings that successful implementation will have in the longer term, particularly from lower rehabilitation costs. Further analysis is provided in Sections 5 and 6 of this report. 3

9 Table 1-1 Clinical benefits measured as the number of bed days saved bed days saved Average weighted cost board Timely thrombolysis Timely carotid savings Ayrshire & Arran , ,018 Borders ,752 Dumfries & Galloway ,629 Fife ,786 Forth Valley ,536 Grampian ,637 Greater Glasgow and Clyde 801 1,809 2, ,130 Highland ,500 Island Boards ,550 Lanarkshire , ,420 Lothian , ,616 Tayside ,740 Scotland 4,752 5,859 10, ,944,314 Additional staff required to implement the key recommendations Timely thrombolysis Additional staff will be required to assess, deliver and immediately manage patients receiving thrombolytic therapy. Each board is assumed to require: a band 7 specialist nurse who spends 1 hour assessing each of the 1,900 patients who may be eligible for the therapy. If the responses indicate that the patient may be eligible for the therapy then the nurse is assumed to call for a consultant. Thereafter the nurse will attend patients receiving the therapy for a further 6 hours as the drug is administered and to oversee the initial management. consultant stroke physicians. Each board is assumed to manage with no additional consultant resource during the core weekday hours. The additional workload associated with thrombolysing patients who present during core hours is assumed to displace the existing workload. However, this should reduce as the upfront investment in delivering the therapy is rewarded by having more patients with improved outcomes and consequently discharged earlier. This assumption will be particularly challenging for smaller boards where the consultant may have duties to conduct outwith the main hospital. Seven boards, being those forecast to have more than 30 patients a year presenting for this therapy in the early evening, are forecast to recruit an extra 0.5 whole time equivalent (WTE) consultant each to 4

10 cover five planned activities per week, providing cover until 8pm. All other out of hours work is assumed to be undertaken by on-call arrangements. The total staff required is estimated to be 4.2 WTE nurses, 35 additional planned activities per week to provide consultant resource in the early evening and 760 out of hours call-outs. An analysis of the staffing required by board is provided in Section 5.7. Carotid endarterectomy Delivery of a timely carotid endarterectomy service will require staff to perform an additional 608 carotid endarterectomy procedures. The additional staff required are 1.1 WTE vascular surgeons, 0.65 WTE band 5 and 0.65 WTE band 6 theatre nurses and 0.65 WTE anaesthetist. Most inpatients should be able to receive the procedure during their initial inpatient stay, whilst outpatients are assumed to be admitted for 2 nights, one before and one after the procedure. The benefits from fewer recurrent strokes will reduce the demand for bed days over time. For example, undertaking five carotid endarterectomy procedures within 14 days of the original events, will require a total of 10 bed days (2 night stay in a surgical ward as a maximum) initially but may be rewarded by preventing one recurrent stroke, saving some 27 bed days. However, there may be a timing issue for hospitals since the extra beds and associated services are needed immediately but the overall long term benefit could potentially be over 5 8. Timely CT diagnostics The total number of staff required to provide a timely CT scanning service for patients suspected of a stroke or TIA, and their subsequent management, is estimated to be almost 740 planned activity sessions for stroke consultants to read the images and approximately six band 7 radiographers, six band 6 radiographers, six band 3 helpers and six band 2 clerical officers. Many of these staff will be in place. However, it has not been possible to identify whether any additional staff could be required. Rather, an analysis of the current service provision suggests there is sufficient capacity in the system. An estimated 3.8 WTE additional band 6 business administration managers are forecast to be required across Scotland, in the first year, to support implementation. Estimated costs required to implement the key recommendations The estimated costs of implementing the key recommendations are 3.5 million in the first year. Thereafter the 0.13 million for business support should fall, leaving additional costs to the service of around 3.4 million. 5

11 Table 1 2 analyses the cost by board for each of the three interventions. These costs exclude any costs for additional diagnostics. Provision of an efficient CT scanning service could cost approximately 0.95 million a year. It is not possible to estimate the current costs and thus whether additional costs are required. Table 1-2 Additional costs required to implement key recommendations in SIGN 108 Timely carotid endarterectomy Business admin support board Timely thrombolysis costs Ayrshire & Arran 210,140 33,439 10, ,879 Borders 34,314 32,707 5,150 72,171 Dumfries & Galloway 52,696 10,469 5,150 68,315 Fife 179,205 69,429 10, ,934 Forth Valley 64,006 17,460 5,150 86,616 Grampian 297,275 29,960 10, ,534 Greater Glasgow and Clyde 294, ,189 36, ,917 Highland 259,096 22,427 5, ,673 Island Boards 5,133 7, ,635 Lanarkshire 229, ,210 15, ,921 Lothian 217, ,573 15, ,786 Tayside 178,759 67,819 10, ,878 Scotland 2,022,329 1,377, ,747 3,528,260 Estimated net costs required to implement the key recommendations Comparing the total cost of implementing the guideline with a valuation based on the bed days saved is difficult to interpret. This is because reducing bed days seldom releases additional funding or staff resources; rather the beds are used to manage additional patients or non-stroke patients and staff are re-deployed elsewhere in the board. Despite that caveat, the estimated net cost (before any enhancements are made to the provision of diagnostic services) from implementing SIGN 108 is estimated at approximately 0.6 million in year one, as detailed in Table

12 Table 1-3 budgetary impact for Scotland and boards of SIGN 108 board Estimated savings costs Net cost impact Ayrshire & Arran 198, ,879 55,861 Borders 58,752 72,171 13,419 Dumfries & Galloway 136,629 68,315 ( 68,314) Fife 339, ,934 ( 80,852) Forth Valley 85,536 86,616 1,080 Grampian 182, , ,898 Greater Glasgow and Clyde 608, , ,787 Highland 184, , ,173 Island Boards 26,550 12,635 ( 13,915) Lanarkshire 336, , ,501 Lothian 473, ,786 ( 29,830) Tayside 313, ,878 ( 56,862) Scotland 2,944,314 3,528, ,946 board reports In support of this national report, each board (with the islands combined) has received spreadsheets covering: data from ISD on the incidence and outcome of stroke that has resulted in a hospital admission over the last 3, and the assumptions, values for each key parameter and analysis used to estimate their individual cost and savings. It is hoped that these spreadsheets will provide a framework for boards to enable them to model potential solutions to the challenges presented in implementing the key recommendations in SIGN

13 2 INTRODUCTION 2.1 Objective The objective of this clinical and resource impact assessment is to facilitate more rapid implementation of the key recommendations in SIGN Guideline 108 Management of patients with stroke or TIA: assessment, investigation, immediate management and secondary prevention 3. The report provides each board with an estimate of the resources and costs required to implement the recommendations, together with the associated clinical benefits. This report does not reproduce the SIGN guideline and should be read in conjunction with it. A recent Audit Commission report concluded that the lack of robust information on the resources required and associated costs including any potential savings was one of the biggest difficulties in developing plans to implement clinical guidelines 9. This report aims to provide such information to support implementation of the recommendations in boards. It does not attempt to cost all aspects of the current diagnosis and management of patients with stroke or transient ischaemic attack (TIA). No cost effectiveness analyses are presented within this report. 2.2 Key recommendations Timing is a central theme throughout SIGN 108. The changes in practice that are required to facilitate implementation of the key recommendations are not necessarily a marked departure from current clinical practice or the patient pathway of care within the acute setting. Rather, successful implementation requires doing the same things to a more demanding timescale. Stroke and TIA s share common morbidity or co-morbidities with primarily, coronary heart disease, peripheral vascular disease and diabetes 10, each of which in turn require the same resources, be that the Scottish Ambulance Service (SAS), radiological diagnostics or indeed theatre time. For each of the key recommendations, a synopsis of the relevant considerations that have been taken into account as part of the workflow arrangements which led to the preparation of this report is noted below. Timely thrombolysis Emergency medical services should be redesigned to facilitate rapid access to specialist stroke services (recommendation 2.1) The costings have focussed on the front line diagnostics required to determine the stroke type; a computed tomography (CT) scanner in the first instance. Adopting a protocol for SAS that enables the paramedics to recognise a potential stroke patient and to deliver the person to a hospital with a CT scanner rather than the nearest place of safety should reduce the number of secondary transfers from non-ct scanning Accident & Emergency (A&E) departments. However, this may result in potentially 8

14 longer journeys in both distance and time. Under these circumstances, the use of the air ambulance service may be required as the only method of transport suitable to move patients to an appropriate place for thrombolytic therapy within the period of 4.5 hours of symptom onset. Stroke patients requiring admission to hospital should be admitted to a stroke unit staffed by a co-ordinated multidisciplinary team with a special interest in stroke care (recommendation 2.2) All of Scotland s hospitals which have a CT scanner also have a stroke unit associated 11 ; either as an acute receiving unit, a rehabilitation unit or a combination of both. Geographical variations between and within boards means that not all hospitals are in a position to offer thrombolytic therapy or to provide surgical facilities for carotid endarterectomy. Recruiting specialist nurses to deliver timely thrombolysis is judged to be sufficient to ensure all hospitals admitting stroke patients are staffed by a co-ordinated multidisciplinary team with a special interest in stroke care. All patients with suspected stroke should have brain imaging immediately on presentation (recommendation 2.3.1) The imaging may take place following assessment at A&E or by elective attendance at a neurovascular clinic. The report has quantified the demand for CT scanning services in all settings and assessed the capacity required to meet this demand. Patients requiring assessment for timely thrombolysis would still require to be seen on an urgent basis. Patients admitted with stroke within 4.5 hours of definite onset of symptoms, who are considered suitable, should be treated with 0.9 mg/kg (up to maximum 90 mg) intravenous rt-pa (recommendation 2.4) The process of delivery of the thrombolytic agent can, depending on the weight of the particular patient, take up to 1.5 hours to be delivered. Thereafter a period of 6 hours must be allowed for patient recovery in an environment akin to either a high dependency unit or an intensive care unit and thus require dedicated specialist care. Timely carotid endarterectomy All patients with non-disabling acute stroke syndrome/tia in the carotid territory who are potential candidates for carotid surgery should have carotid imaging (recommendation 2.3.2) All patients with carotid artery territory stroke or TIA should be considered for carotid endarterectomy as soon as possible after the index event (recommendation 2.6.1) Carotid endarterectomy (on the internal carotid artery ipsilateral to the cerebrovascular event) should be considered in all: - male patients with a carotid artery stenosis of 50 99% (by NASCET method) - female patients with a carotid artery stenosis of 70 99% 9

15 For all patients, carotid endarterectomy should be performed as soon as the patient is stable and fit for surgery, ideally within 2 weeks of the initial event (recommendation 2.6) Implementing these recommendations will require arrangements to be made for possible surgical intervention as soon as possible after initial symptom onset; ideally within less than 14 days for maximum potential benefit based on the number needed to treat (NNT) to avoid a single recurring stroke event. Given the tendency for this procedure to be geared towards those with mild strokes (modified Rankin Scale [mrs] 2) and TIA s the provision of this service must encompass not only those who have been admitted, but also those who have had an initial referral to a neurovascular outpatient clinic. 2.3 Document overview Section 3 describes the methodology used to estimate the clinical benefit (which is expressed as a number of bed days saved with the associated weighted average variable costs [excluding overheads]), the estimate of resources required (including cost calculations for consulting and non-consulting staff) and the provisions for consumable costs, theatre operating rates per hour and the weighted average cost of the essential radiological scans. Section 4 describes the methodology adopted together with the background with regards to stroke. This involved the development of a model to predict mortality at 1 month following a first hospital admission, and the predictability of recurrent events that result in a re-admission at 3 months following an initial discharge for those who have survived. Sections 5, 6 and 7 report the estimates for each of the key recommendation groupings; timely thrombolysis, timely carotid endarterectomy and timely CT diagnostics in more detail. Sensitivity analyses are provided within each section. The detailed appendices contain the following information: Appendix 1 lists the 15 clinically important recommendations and explains why some were excluded from further study. Appendix 2 acknowledges those who have contributed to the development of this report. Appendix 3 provides a flowchart on the resource impact assessment process and implementing guidelines. Appendix 4 details the International Classification of Disease (ICD 10) codes as they relate to cerebrovascular disease. Appendix 5 details the epidemiological model for Scotland that has been derived from the analysis of mortality records from the General Register Office for Scotland (GROS) and Scottish Morbidity Admission Records (SMR01) databases from Information Services Division (ISD). Appendix 6 illustrates how these data has been used to drive the consolidated demand for admissions, re-admissions and survival rates for patients who are both inside and outside the follow up window of one year. 10

16 Appendix 7 provides an index to the sources of information which are published annually by ISD in relation to costs in Scotland. Further information For further information on this report, to obtain a copy, or to provide feedback on its usefulness please contact: Joyce Craig Lead Health Economist Quality Improvement Scotland Delta House 50 West Nile Street GLASGOW G1 2NP joyce.craig@nhs.net 11

17 3 BACKGROUND AND METHODOLOGY 3.1 Introduction Stroke is the third biggest cause of mortality and the primary cause of acquired disability in the adult 1. It is estimated that hospital care for patients with a stroke accounts for 7% of total beds occupied in Scottish hospitals and that the total cost of care represents nearly 5% of the entire Scotland budget 11. The outcome for patients following stroke is generally referred to in terms of survival, functional status (dependence and disability) and the risk of recurrence Recurrent stroke carries a higher risk of mortality and can lead to profound long term disability in those who have survived their initial stroke, depending on the base level of impairment from that event. Implementing the key recommendations in SIGN 108 is anticipated to improve patient outcomes by enabling the appropriate therapies to be administered in the optimal time frames. Delivery of timely carotid endarterectomy should reduce the risk of a recurrent cerebrovascular event. Delivery of timely thrombolysis should reduce the level of possible dependency following a stroke and facilitate earlier hospital discharge. 3.2 Methodology to estimate clinical benefit The mean length of stay as a result of stroke in Scottish hospitals is estimated at 27 days per event. This is a weighted average of the mean length of stay of 25.4 days reported by the Scottish Stroke Care Audit (SSCAS) 11 and the mean length of stay of 28.9 days for ischaemic stroke and 27.2 days for inconclusive stroke, reported by ISD 15. Preventing a stroke event that would otherwise result in either a repeat admission (if the patient had already been admitted previously and then subsequently discharged) or a first ever admission (if the patient had previously been seen at a neurovascular outpatient clinic) is assumed to save 27 bed days. SIGN 108 reports the clinical studies that demonstrate treatment with recombinant tissue plasminogen activator (rt-pa) within 4.5 hours of symptom onset improves the outcome of some but not all patients who are eligible for treatment. It should not be seen as a cure for ischaemic stroke, including the possibility of preventing recurrent events; rather for some patients successful therapy can reduce the severity, including the level of disability or impairment, which can accompany the event. In the pathway from admission to final discharge the outcome from thrombolytic therapy has been estimated to enable 10% of patients to make a full recovery and be discharged early (the Lazarus Effect ), whilst 45% of patients will have a significantly improved outcome enabling earlier discharge 16. The question of time from symptom onset is fundamental in the delivery of thrombolytic therapy. Patients who arrive at hospital where the time of symptom onset is judged to be greater than 4.5 hours will not be eligible for therapy under the current licence for use. In the preparation of this report, the ICD 10 code for inconclusive stroke (I64) has been taken as an indicator, given the geographical variations within the epidemiology 12

18 (see Section 4) of the percentage of patients who currently do not arrive within the appropriate time frame for thrombolytic consideration. The time from symptom onset is also relevant for the effective provision of carotid endarterectomy. Section of SIGN 108 demonstrates that the NNT to prevent one recurrent event rises as the time from symptom onset progresses. To calculate the clinical benefit from carotid endarterectomy, this report assumes boards are able to provide the procedure within 14 days of the event, in line with the SIGN recommendation. This maximises the potential clinical benefit. This section of SIGN 108 also notes that A proportion of patients who are severely disabled immediately following their stroke event can make rapid recovery such that they meet the criteria used in the studies for carotid endarterectomy. This report assumes thrombolysis can improve the outcome of patients sufficiently to enable them to be considered for carotid evaluation and possible surgical intervention prior to discharge. Following administration of thrombolytic therapy, carotid artery occlusion and the anterior circulation infarcts that stem from this type of underlying cause have been reported as a determinant of poor outcome in the 3 months following treatment 17, when by inference the risk of a recurrent event is greatest in this particular subtype of ischaemic stroke (see Section 4) This may be reduced by carotid endarterectomy. Not all patients who arrive within 4.5 hours of symptom onset will be eligible for thrombolytic therapy. The Summary of Product Characteristics ( does not recommend use for patients over the age of 80. Other contraindications include patients with severe stroke as assessed clinically and/or by appropriate imaging techniques, patients receiving oral anticoagulants and evidence of any haemorrhage events, including liver disease. These exclusions have been modelled in this report by assuming a specialist nurse trained in thrombolytic therapy undertakes an assessment in an A&E environment. For those patients who are assessed as unsuitable for thrombolysis but candidates for carotid endarterectomy, rapid access to carotid imaging and potential surgical intervention should be facilitated in order to meet the 14 day timeline for maximum clinical benefit. Due to the current low numbers being treated for thrombolysis this element has been difficult to model for this report, however it will be a significant factor to consider as implementation progresses. 3.3 Methodology to estimate resources required and associated costs and savings Appendix 3 outlines the process developed and adopted to produce this report. Once the key themes and associated recommendations had been identified, draft patient pathways showing the changes required to implement each key recommendation were developed. These were informed by the results of a literature search on the epidemiology of stroke. ISD also provided extensive data on Scottish epidemiology and the facilities available at each board. These data were combined with knowledge gained from intensive discussions with a number of the members of the guideline development group, feedback from members of the stroke managed clinical networks 13

19 and on-site visits. Discussions were also held with representatives from SAS. Planners from SAS modelled the implications of changing the destination for potential stroke patients, depending on the availability of CT scanning facilities. The data from these sources were combined into several models. An independent expert, with extensive knowledge of SSCAS was asked to validate the outcomes of the epidemiological model and other clinical experts were asked to validate the pathways assumed for their board. Where possible published resource and cost data from ISD were used and supplemented by other published data as appropriate. Occasionally, unpublished sources were used and referenced. The models were made available to clinicians in all mainland boards for review, supported, where possible, by meetings to discuss the findings. Data values and associated spreadsheets were quality assured by an independent health economist. An evaluation of the usefulness of this report to boards as they seek to implement the recommendations in SIGN 108 will be commissioned by Quality Improvement Scotland. 3.4 Methodology to estimate cost of resources and associated savings The cost of rt-pa alteplase was taken from BNF 56 ( being: 10 mg 135 excluding VAT; including VAT at 17.5% 20 mg 180 excluding VAT; including VAT at 17.5% 50 mg 300 excluding VAT; including VAT at 17.5%. For the purpose of this report the cost of alteplase has been taken as an average of 80 mg at a cost of 723 including VAT. Costs for events such as SAS journeys, A&E attendance, radiology attendance, outpatient consultation, inpatient stay and theatre costs per hour are routinely published by ISD ( The costs adopted in this report are a weighted average taking into consideration the total costs (overheads, staff resources, supplies and consumables) and dividing this by the number of events or patients who have attended. To calculate the value of a bed day saved the inpatient rate per day has been adjusted to remove overheads and theatre costs, leaving primarily staff costs plus some consumables that would normally be required during an inpatient stay. This approach, primarily applied to the cost data for the mainland boards, gives a Scottish mean weighted cost for an overnight stay in a general medical ward, where stroke unit costs are recorded, of 277 per day (see Table 1 1). 14

20 Appendix 7 details all of the costs that have been used in this report. These are available to download from the ISD website at On an individual board level the supporting excel spreadsheets have the facility to change the cost matrix should the need arise. The mean staff costs for the additional staff required as a result of implementing SIGN 108 have been taken as the mid-point within the Agenda for Change pay scales as it affects both consulting and non-consulting staff. This salary mid-point is grossed up by 22% to take account of the current rate of national insurance contributions and pension overhead. Translating costs into the relevant WTE for the additional members of staff requires a further adjustment [52/42] to account for abstractions due to holiday entitlement and training. Table 3 1 details the mid-point on the pay scale bands under the current terms of employment in the effective from 1 April 2008 for nonconsulting staff. Table 3 2 details the mid-point on the pay scale bands under the current terms of employment in the effective from 1 April 2008 for consulting staff. Full details of employment contracts for both consulting and non_consulting staff are available from Table 3-1 Gross salary costs taken as mid-point within each salary band including and adjustment for WTE costs for non-consulting staff (Agenda for Change) Band Mid-point Base 22% Gross Gross WTE ,428 3,174 17,602 21, ,307 3,588 19,895 24, ,038 4,188 23,226 28, ,797 5,015 27,812 34, ,141 6,191 34,332 42, ,603 7,393 40,996 50,757 Table 3-2 Gross salary costs taken as the mid-point salary band including and adjustment for WTE costs for consulting staff (pay circular M&D 3/2008) Pay Scale Point Base 22% Gross Gross WTE MC72/LC ,049 19, , ,996 Clinical Excellence Awards 5 14,565 3,204 17,769 22, ,614 22, , ,996 Cost per individual session 397 Annual cost of one session per week 20,666 15

21 The cost for carotid endarterectomy as a weighted average for Scotland has been derived from the total expected costs of surgery in each of the individual boards to include; a consultant outpatient appointment with a vascular surgeon, a secondary confirmation of carotid disturbance (MRI equivalent) in order to guide the surgical procedure, theatre time at 1.5 hours and a post-surgical carotid Doppler examination. Table 3 3 details the calculation for carotid endarterectomy across the boards in Scotland for those patients who either return to a stroke ward or are cared for in a surgical ward having been previously discharged or attended a neurovascular outpatient clinic. 16

22 Table 3-3 Consolidated surgical costs for carotid endarterectomy, based on whether the patient returns to a stroke ward or has a separate admission to a surgical ward Costing methodoly for procedures carried out on existing inpatients where after surgery the patient returns back to the stroke (general medicine) ward Scotland total Ayrshire & Arran Borders Dumfries & Galloway Number of Cases Fife Forth Valley Grampian Greater Glasgow & Clyde Highland Island Boards Lanarkshire Lothian Tayside Consultant Outpatient - Vascular Surgery Secondary Confirmation - MRI Equivalent Theatre Costs Hours 1,289 1,563 1,463 1,317 1,116 1,425 1,674 1,289 1,025 1,320 1,721 1,298 Secondary Confirmation - Ultrasound Post Surgery Unit Costs - Inpatient Carotid Surgery 1,855 1,593 1,807 1,789 1,762 1,580 1,759 2,097 2,140 1,500 1,647 2,023 1,679 0 Costs for Inpatient Carotid Surgery 732,696 50,968 16,266 23,258 47,581 30,023 61, ,640 47,074 12,003 79, ,210 52,045 Estimated number of cases carried out to 31 March 2008 for analysis of additional cases Costing methodology for procedures carried out on patients requiring a new admission to a surgical ward either from outpatient attendance or following early discharge from a stroke ward Scotland total Ayrshire & Arran Borders Dumfries & Galloway Number of Cases Fife Forth Valley Grampian Greater Glasgow & Clyde Highland Island Boards Lanarkshire Lothian Tayside Consultant Outpatient - Vascular Surgergy Secondary Confirmation - MRI Equivalent Inpatient Surgery - Cost Per Day's Stay Theatre Costs Hours 1,289 1,563 1,463 1,317 1,116 1,425 1,674 1,289 1,320 1,721 1,298 Secondary Confirmation - Ultrasound Post Surgery Unit Costs - Inpatient Carotid Surgery 2,443 2,229 2,367 2,297 2,326 2,120 2,301 2,660 2, ,069 2,725 2,244 Costs for Outpatient Carotid Surgery 1,869, ,438 40,245 45,941 95,376 67, , ,501 98, , ,175 89,755 Estimated number of cases carried out to 31 March 2008 for analysis of additional cases

23 3.5 Limitations The current report has a number of limitations in that it is primarily based on an overall model which encompasses a number of smaller models. The epidemiological model balances across Scotland and is within 10% for individual boards. It has therefore been assumed to be robust and to generalise to events in future. Other important assumptions are set out below. On full implementation of SIGN 108, boards will not transfer patients across boundaries for thrombolysis or carotid endarterectomy. An appropriate number of beds are available in the short term to accommodate the anticipated demand for patients receiving timely thrombolysis and carotid endarterectomy. Such interventions will reduce the demand for beds in the longer term but there will be a mismatch between the immediate requirements and realising the longer term benefit. Each hospital modelled to deliver thrombolysis has sufficient beds in a high dependency or intensive care unit available to accommodate the patients receiving such therapy. These patients should be monitored for adverse events during the immediate few hours after delivery of the drug. No growth in the number of stroke patients managed beyond the 2007 mid-year baseline is assumed. Staff and facilities will be shared efficiently across Scotland. For example, there may be a need for an extra 4 WTE specialist nurses across Scotland to provide timely thrombolysis. This may equate to, say, 0.2 WTE of a nurse in one hospital. Recruiting such small increments of staff may not be possible, in which case the staff numbers required will be a material underestimate. The terminology refers to bed days saved, being bed days that will no longer be required because the intervention reduces the risk of future strokes. In reality these beds are likely to be occupied by patients with other conditions and thus the beds will still be used. The analyses do not aggregate the resources required to implement a revised service with the potential savings from fewer clinical events. This is partly because of timing differences, but also because the two estimates are made using different approaches. However, users may wish to consider a net table. Some significant cost categories have been excluded, particularly the cost of service redesign and associated training and recruitment costs. The role of telemedicine has also not been considered. The analysis is not intended to be an absolute definitive solution to the implementation challenges that are faced by boards in Scotland either currently or when implementing SIGN 108. Much of the work which is being presented here will have to be repeated as time progresses, particularly as the true admission pattern for thrombolytic therapy is revealed at individual board level. 18

24 4 SCOTTISH STROKE EPIDEMIOLOGY 4.1 Introduction In order to better understand how implementing the key recommendations in SIGN 108 can improve patient outcomes it has been necessary to undertake an epidemiological study of stroke as it relates to hospital admissions, rates of survival, the possibility of recurrence and by inference the likelihood of dependency. The principal drivers behind this study have been taken by way of extension from the published work of the Oxfordshire Community Stroke Project (OCSP) and the Community- Based Stroke Incidence in a Scottish Population, the Scottish Borders Stroke Study (SBSS) 2. This section details the work that has been undertaken at both a national and local level in relation to stroke for the ended 31 March 2006, 2007 and From the information gathered, a model has been developed at a national level which predicts the mortality of patients who have been admitted to hospital for the first time as a result of their stroke to within 99% accuracy. At board level the same model can predict mortality, to within 90% or greater accuracy, in each of the Incidence of a first hospital admission as a result of stroke or TIA Scotland has some of the best health service data in the world, in particular the SMR01 database of hospital admission records and the GROMR database of mortality records, which are held by ISD and GROS respectively. The high quality data, consistency, national coverage and the specific ability to link data between the two databases in order to allow patient based analysis and follow up has been fundamental in the analysis of patients who have been admitted to hospital for stroke or TIA. Following the protocols defined in both the SBSS and OCSP in relation to first ever stroke both ISD and GROS were asked to deliver data based on the following selection criteria from the ICD 10 codes for cerebrovascular disease. Full details of the codes are provided in Appendix 4: For hospital admissions: Include all patients who had a unique admission record (with subsequent discharge) in the range of ICD 10 codes specified for cerebrovascular disease including TIA s for each of the ended 31 March March 2008 inclusive. For mortality records: Include all deaths recorded (including autopsy) in the range of ICD 10 codes specified for cerebrovascular disease including TIA s for each of the ended 31 March March 2008 inclusive. 19

25 Linked data: For hospital admissions, link the patient identification number and scan through the historical database records for a period of up to 10 and eliminate any corresponding record that has had a previous entry in any of the ICD 10 codes specified. For mortality records, link the patient identification number and scan through the SMR01 database records and eliminate any corresponding admission record found that had an entry in any of the ICD 10 codes specified. The resultant output combines unique records for patients who have either been admitted on the first occasion with a diagnosis of stroke or TIA (discharge code) or have died in the community as a result of their stroke, having never been admitted to hospital historically for the condition. The unique records of hospital admissions can be indexed within each of the individual and linked back into the SMR01 database to search for further information based on the patients identification number. Historical information such as the last known hospital admission prior to the current event has revealed the growing problem of liver toxicity, brought about through drug and alcohol abuse, particularly in the younger cohort of patients being admitted for stroke in Scotland. Whilst for older patients, the increasing significance of diabetes type 2 and clinical obesity in relation to stroke is becoming more evident. Likewise, cross referencing the linked patient identification numbers for each of the in question to the GROMR database has provided detailed information on the survival rates following stroke at 1, 3, 6 and 12 months, regardless of whether the patient died in hospital or in the community after having been discharged 19. Appendices 5 1 to 5 5 provide details of the consolidated results for Scotland for the year ending 31 March 2007, which is the most recent year where all data collected through the SMR01 database is most complete. As a result of the extensive epidemiological studies carried out in the preparation of this report, there is some evidence to suggest that the rate of recurrence of stroke, but not TIA, in patients who have originally presented for a hospital admission in an historical period in excess of 1 year is increasing. Table 4 1 analyses hospital admissions in the ending 31 March 2005, 2006 and 2007, being the last three in which the ISD SMR01 database has complete hospital submission records for patient admittance and subsequent re-admittance following discharge. Recurrent events are linked to a first ever admission in each of the in question. The difference between total first ever events and actual admissions indicates that a patient cohort has been admitted from a prior period and that the percentage of patients this number represents is increasing. 20