Estimating the effectiveness and cost-effectiveness of establishing additional endovascular Thrombectomy stroke Centres in England: a discrete event simulation

Extending mechanical thrombectomy service provision to 24/7: a break-even analysis

BACKGROUND

Comprehensive stroke centres across England have developed investment proposals, showing the estimated increases in mechanical thrombectomy (MT) treatment volume that would justify extending the standard hours to a 24/7 service provision. These investment proposals have been developed taking a financial accounting perspective, that is by considering the financial revenues from tariff income. However, given the pressure put on local health authorities to provide value for money services, an affordability question emerges. That is, at what additional MT treatment volume the additional treatment costs are offset by the additional health economic benefits, that is quality-adjusted life years (QALYs) and societal cost savings, generated by administering MT compared to standard care.

METHODS

A break-even analysis was conducted to identify the additional MT treatment volume required. The incremental hospital-related costs associated with the 24/7 MT extension were estimated using information and parameters from four relevant business cases. The additional societal cost savings and health benefits were estimated by adapting a previously developed Markov chain-based model.

RESULTS

The additional hospital-related annual costs for extending MT to a 24/7 service were estimated at a mean of £3,756,818 (range £1,847,387 to £5,092,788). On average, 750 (range 246 to 1,571) additional eligible stroke patients are required to be treated with MT yearly for the proposed 24/7 service extension to be affordable from a health economic perspective. Overall, the additional facility and equipment costs associated with the 24/7 extension would affect this estimate by 20%.

CONCLUSIONS

These findings support the ongoing debate regarding the optimal levels of MT treatment required for a 24/7 extension and respective changes in hospital organisational activities. They also highlight a need for a regional-level coordination between local authorities and hospital administrations to ensure equity provision in that stroke patients can benefit from MT and that the optimal MT treatment volume is reached. Future studies should contemplate reproducing the presented analysis for different health service provision settings and decision making contexts.

Cost-effectiveness of improvement strategies for reperfusion treatments in acute ischemic stroke: a systematic review

BACKGROUND

Reducing delays along the acute stroke pathway significantly improves clinical outcomes for acute ischemic stroke patients eligible for reperfusion treatments. The economic impact of different strategies reducing onset to treatment (OTT) is crucial information for stakeholders in acute stroke management. This systematic review aimed to provide an overview on the cost-effectiveness of several strategies to reduce OTT.

METHODS

A comprehensive literature search was conducted in EMBASE, PubMed, and Web of Science until January 2022. Studies were included if they reported 1/ stroke patients treated with intravenous thrombolysis and/or endovascular thrombectomy, 2/ full economic evaluation, and 3/ strategies to reduce OTT. The Consolidated Health Economic Evaluation Reporting Standards statement was applied to assess the reporting quality.

RESULTS

Twenty studies met the inclusion criteria, of which thirteen were based on cost-utility analysis with the incremental cost-effectiveness ratio per quality-adjusted life year gained as the primary outcome. Studies were performed in twelve countries focusing on four main strategies: educational interventions, organizational models, healthcare delivery infrastructure, and workflow improvements. Sixteen studies showed that the strategies concerning educational interventions, telemedicine between hospitals, mobile stroke units, and workflow improvements, were cost-effective in different settings. The healthcare perspective was predominantly used, and the most common types of models were decision trees, Markov models and simulation models. Overall, fourteen studies were rated as having high reporting quality (79%-94%).

CONCLUSIONS

A wide range of strategies aimed at reducing OTT is cost-effective in acute stroke care treatment. Existing pathways and local characteristics need to be taken along in assessing proposed improvements.

A cost-utility analysis comparing endovascular coiling to neurosurgical clipping in the treatment of aneurysmal subarachnoid haemorrhage

Endovascular coiling (EC) has been identified in systematic reviews and meta-analyses to produce more favourable clinical outcomes in comparison to neurosurgical clipping (NC) when surgically treating a subarachnoid haemorrhage from a ruptured aneurysm. Cost-effectiveness analyses between both interventions have been done, but no cost-utility analysis has yet been published. This systematic review aims to perform an economic analysis of the relative utility outcomes and costs from both treatments in the UK. A cost-utility analysis was performed from the perspective of the National Health Service (NHS), over a 1-year analytic horizon. Outcomes were obtained from the randomised International Subarachnoid Aneurysm Trial (ISAT) and measured in terms of the patient's modified Rankin scale (mRS) grade, a 6-point disability scale that aims to quantify a patient's functional outcome following a stroke. The mRS score was weighted against the Euro-QoL 5-dimension (EQ-5D), with each state assigned a weighted utility value which was then converted into quality-adjusted life years (QALYs). A sensitivity analysis using different utility dimensions was performed to identify any variation in incremental cost-effectiveness ratio (ICER) if different input variables were used. Costs were measured in pounds sterling (£) and discounted by 3.5% to 2020/2021 prices. The cost-utility analysis showed an ICER of - £144,004 incurred for every QALY gained when EC was utilised over NC. At NICE's upper willingness-to-pay (WTP) threshold of £30,000, EC offered a monetary net benefit (MNB) of £7934.63 and health net benefit (HNB) of 0.264 higher than NC. At NICE's lower WTP threshold of £20,000, EC offered an MNB of £7478.63 and HNB of 0.374 higher than NC. EC was found to be more 'cost-effective' than NC, with an ICER in the bottom right quadrant of the cost-effectiveness plane-indicating that it offers greater benefits at lower costs. This is supported by the ICER being below the NICE's threshold of £20,000-£30,000 per QALY, and both MNB and HNB having positive values (> 0).

Moving from traditional to more advanced treatments in stroke care is cost-effective: A case study from Greece

OBJECTIVES

Stroke is the most common cause of disability in high-income countries. Several countries offer a limited range of advanced treatments with implications for outcomes, disability and costs. This study estimates the burden of disability that could have been avoided through the transition from traditional (no intravenous thrombolytic therapy (IVT), or endovascular thrombectomy (EVT)) to modern stroke treatments (treatment in stroke units, IVT and EVT). We perform a cost-effectiveness analysis comparing best practice with traditional stroke care, using Greece as a case study.

MATERIALS AND METHODS

A Markov model was used to calculate costs and Quality Adjusted Life Years (QALYs) for each treatment strategy, using a lifetime horizon. Data for model inputs were derived from meta-analyses of trials, and national and international cost databases. Sensitivity analyses were also performed to address potential uncertainty and test the robustness of the findings.

RESULTS

Incremental effectiveness comprised 0.22 QALYs per patient and year. Best practice was cost-effective for more than 90% of all iterations (ICER for the baseline scenario: €2,109.25/QALY). Sensitivity analysis demonstrated that the findings remain robust. Considering the stroke incidence in Greece, the annual additional cost to implement best practice was calculated to be between 0.07%-0.15% of the total health expenditure.

CONCLUSION

Best practice stroke treatment was cost-effective and affordable in a case study based on Greece. The results could be leveraged by including effects of preventive policies and rehabilitation. They also highlight the importance of adopting modern treatment strategies from a cost-effectiveness perspective, apart from the improved clinical outcomes.

Improving emergency treatment for patients with acute stroke: the PEARS research programme, including the PASTA cluster RCT

Background

Intravenous thrombolysis and intra-arterial thrombectomy are proven emergency treatments for acute ischaemic stroke, but they require rapid delivery to selected patients within specialist services. National audit data have shown that treatment provision is suboptimal.

Objectives

The aims were to (1) determine the content, clinical effectiveness and day 90 cost-effectiveness of an enhanced paramedic assessment designed to facilitate thrombolysis delivery in hospital and (2) model thrombectomy service configuration options with optimal activity and cost-effectiveness informed by expert and public views.

Design

A mixed-methods approach was employed between 2014 and 2019. Systematic reviews examined enhanced paramedic roles and thrombectomy effectiveness. Professional and service user groups developed a thrombolysis-focused Paramedic Acute Stroke Treatment Assessment, which was evaluated in a pragmatic multicentre cluster randomised controlled trial and parallel process evaluation. Clinicians, patients, carers and the public were surveyed regarding thrombectomy service configuration. A decision tree was constructed from published data to estimate thrombectomy eligibility of the UK stroke population. A matching discrete-event simulation predicted patient benefits and financial consequences from increasing the number of centres.

Setting

The paramedic assessment trial was hosted by three regional ambulance services (in north-east England, north-west England and Wales) serving 15 hospitals.

Participants

A total of 103 health-care representatives and 20 public representatives assisted in the development of the paramedic assessment. The trial enrolled 1214 stroke patients within 4 hours of symptom onset. Thrombectomy service provision was informed by a Delphi exercise with 64 stroke specialists and neuroradiologists, and surveys of 147 patients and 105 public respondents.

Interventions

The paramedic assessment comprised additional pre-hospital information collection, structured hospital handover, practical assistance up to 15 minutes post handover, a pre-departure care checklist and clinician feedback.

Main outcome measures

The primary outcome was the proportion of patients receiving thrombolysis. Secondary outcomes included day 90 health (poor status was a modified Rankin Scale score of > 2). Economic outputs reported the number of cases treated and cost-effectiveness using quality-adjusted life-years and Great British pounds.

Data sources

National registry data from the Sentinel Stroke National Audit Programme and the Scottish Stroke Care Audit were used.

Review methods

Systematic searches of electronic bibliographies were used to identify relevant literature. Study inclusion and data extraction processes were described using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

Results

The paramedic assessment trial found a clinically important but statistically non-significant reduction in thrombolysis among intervention patients, compared with standard care patients [197/500 (39.4%) vs. 319/714 (44.7%), respectively] (adjusted odds ratio 0.81, 95% confidence interval 0.61 to 1.08; p = 0.15). The rate of poor health outcomes was not significantly different, but was lower in the intervention group than in the standard care group [313/489 (64.0%) vs. 461/690 (66.8%), respectively] (adjusted odds ratio 0.86, 95% confidence interval 0.60 to 1.2; p = 0.39). There was no difference in the quality-adjusted life-years gained between the groups (0.005, 95% confidence interval –0.004 to 0.015), but total costs were significantly lower for patients in the intervention group than for those in the standard care group (–£1086, 95% confidence interval –£2236 to –£13). It has been estimated that, in the UK, 10,140–11,530 patients per year (i.e. 12% of stroke admissions) are eligible for thrombectomy. Meta-analysis of published data confirmed that thrombectomy-treated patients were significantly more likely to be functionally independent than patients receiving standard care (odds ratio 2.39, 95% confidence interval 1.88 to 3.04; n = 1841). Expert consensus and most public survey respondents favoured selective secondary transfer for accessing thrombectomy at regional neuroscience centres. The discrete-event simulation model suggested that six new English centres might generate 190 quality-adjusted life-years (95% confidence interval –6 to 399 quality-adjusted life-years) and a saving of £1,864,000 per year (95% confidence interval –£1,204,000 to £5,017,000 saving per year). The total mean thrombectomy cost up to 72 hours was £12,440, mostly attributable to the consumables. There was no significant cost difference between direct admission and secondary transfer (mean difference –£368, 95% confidence interval –£1016 to £279; p = 0.26).

Limitations

Evidence for paramedic assessment fidelity was limited and group allocation could not be masked. Thrombectomy surveys represented respondent views only. Simulation models assumed that populations were consistent with published meta-analyses, included limited parameters reflecting underlying data sets and did not consider the capital costs of setting up new services.

Conclusions

Paramedic assessment did not increase the proportion of patients receiving thrombolysis, but outcomes were consistent with improved cost-effectiveness at day 90, possibly reflecting better informed treatment decisions and/or adherence to clinical guidelines. However, the health difference was non-significant, small and short term. Approximately 12% of stroke patients are suitable for thrombectomy and widespread provision is likely to generate health and resource gains. Clinician and public views support secondary transfer to access treatment.

Future work

Further evaluation of emergency care pathways will determine whether or not enhanced paramedic assessment improves hospital guideline compliance. Validation of the simulation model post reconfiguration will improve precision and describe wider resource implications.

Trial registration

This trial is registered as ISRCTN12418919 and the systematic review protocols are registered as PROSPERO CRD42014010785 and PROSPERO CRD42015016649.

Funding

The project was funded by the National Institute for Health and Care Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 10, No. 4. See the NIHR Journals Library website for further project information.

Discrete-Event Simulation to Model the Thrombolysis Process for Acute Ischemic Stroke Patients at Urban and Rural Hospitals

Background: Effective treatment with tissue plasminogen activator (tPA) critically relies on rapid treatment. Door-to-needle time (DNT) is a key measure of hospital efficiency linked to patient outcomes. Numerous changes can reduce DNT, but they are difficult to trial and implement. Discrete-event simulation (DES) provides a way to model and determine the impact of process improvements.

Methods: A conceptual framework was developed to illustrate the thrombolysis process; allowing for treatment processes to be replicated using a DES model developed in ARENA. Activity time duration distributions from three sites (one urban and two rural) were used. Five scenarios, three process changes, and two reductions in activity durations, were simulated and tested. Scenarios were tested individually and in combinations. The primary outcome measure is median DNT. The study goal is to determine the largest improvement in DNT at each site.

Results: Administration of tPA in the imaging area resulted in the largest median DNT reduction for Site 1 and Site 2 for individual test scenarios (12.6%, 95% CI 12.4–12.8%, and 8.2%, 95% CI 7.5–9.0%, respectively). Ensuring that patients arriving via emergency medical services (EMS) remain on the EMS stretcher to imaging resulted in the largest median DNT improvement for Site 3 (9.2%, 95% CI 7.9–10.5%). Reducing both the treatment decision time and tPA preparation time by 35% resulted in a 11.0% (95% CI 10.0–12.0%) maximum reduction in median DNT. The lowest median and 90^th percentile DNTs were achieved by combining all test scenarios, with a maximum reduction of 26.7% (95% CI 24.5–28.9%) and 17.1% (95% CI 12.5–21.7%), respectively.

Conclusions: The detailed conceptual framework clarifies the intra-hospital logistics of the thrombolysis process. The most significant median DNT improvement at rural hospitals resulted from ensuring patients arriving via EMS remain on the EMS stretcher to imaging, while urban sites benefit more from administering tPA in the imaging area. Reducing the durations of activities on the critical path will provide further DNT improvements. Significant DNT improvements are achievable in urban and rural settings by combining process changes with reducing activity durations.

Return on Investment in Endovascular Care: The Case of Endovascular Reperfusion Alberta

OBJECTIVE

We examined the return on investment (ROI) from the Endovascular Reperfusion Alberta (ERA) project, a provincially funded population-wide strategy to improve access to endovascular therapy (EVT), to inform policy regarding sustainability.

METHODS

We calculated net benefit (NB) as benefit minus cost and ROI as benefit divided by cost. Patients treated with EVT and their controls were identified from the ESCAPE trial. Using the provincial administrative databases, their health services utilization (HSU), including inpatient, outpatient, physician, long-term care services, and prescription drugs, were compared. This benefit was then extrapolated to the number of patients receiving EVT increased in 2018 and 2019 by the ERA implementation. We used three time horizons, including short (90 days), medium (1 year), and long-term (5 years).

RESULTS

EVT was associated with a reduced gross HSU cost for all the three time horizons. Given the total costs of ERA were $2.04 million in 2018 ($11,860/patient) and $3.73 million in 2019 ($17,070/patient), NB per patient in 2018 (2019) was estimated at -$7,313 (-$12,524), $54,592 ($49,381), and $47,070 ($41,859) for short, medium, and long-term time horizons, respectively. Total NB for the province in 2018 (2019) were -$1.26 (-$2.74), $9.40 ($10.78), and $8.11 ($9.14) million; ROI ratios were 0.4 (0.3), 5.6 (3.9) and 5.0 (3.5). Probabilities of ERA being cost saving were 39% (31%), 97% (96%), and 94% (91%), for short, medium, and long-term time horizons, respectively.

CONCLUSION

The ERA program was cost saving in the medium and long-term time horizons. Results emphasized the importance of considering a broad range of HSU and long-term impact to capture the full ROI.

Hub-and-spoke model for thrombectomy service in UK NHS practice

Mechanical thrombectomy is a highly effective but time dependent treatment for acute ischaemic stroke due to large vessel occlusion. In the UK, the national clinical guidelines for stroke and National Institute for Health and Care Excellence guidance endorses thrombectomy as an acute stroke treatment, and NHS England commissioned thrombectomy services. However, there are no UK 'real-world' data to verify the efficacy of the hub-and-spoke model in thrombectomy. There are currently 24 tertiary neuroscience centres in the UK that can provide thrombectomy treatment and many of these operate only within working hours. This study is the first to demonstrate that a hub-and-spoke thrombectomy service in routine UK 24/7 clinical practice is as effective and safe as in the setting of randomised controlled clinical trials. However, there are 9.3% of patients accepted for transfer to the thrombectomy centre who did not proceed to thrombectomy, mostly due to delays. Fifty-three per cent of thrombectomy cases were performed outside of standard working hours when transfer delays were increased. A 24/7 thrombectomy service is needed to maximise the benefit to all suitable patients. Measures, including improving workflow and optimising work forces, are needed to minimise the delays and continue to improve the service.

Only a Minority of Thrombectomy Candidates Are Admitted During Night Shift: A Rationale for Diurnal Stroke Care Planning

Background: Widespread quick access to mechanical thrombectomy (MT) for acute ischemic stroke (AIS) is one of the main challenges in stroke care. It is unclear if newly established MT units are required 24 h/7 d. We explored the diurnal admission rate of patients with AIS potentially eligible for MT to provide a basis for discussion of daytime-adapted stroke care concepts. Methods: Data collected from the Baden-Württemberg Stroke Registry in Germany were assessed (2008-2012). We analyzed the admission rate of patients with AIS stratified by the National Institutes of Health Stroke Scale (NIHSS) score at admission in 3-h intervals. An NIHSS score ≥10 was considered a predictor of large vessel occlusion. The average annual admission number of patients with severe AIS were stratified by stroke service level and calculated for a three-shift model and working/non-working hours. Results: Of 91,864, 22,527 (21%) presented with an NIHSS score ≥10. The average admission rates per year for a hospital without Stroke Unit (SU), with a local SU, with a regional SU and a stroke center were 8, 52, 90 and 178, respectively. Approximately 61% were admitted during working hours, 54% in the early shift, 36% in the late shift and 10% in the night shift. Conclusions: A two-shift model, excluding the night shift, would cover 90% of the patients with severe AIS. A model with coverage during working hours would miss ~40% of the patients with severe AIS. To achieve a quick and area-wide MT, it seems preferable for newly implemented MT-units to offer MT in a two-shift model at a minimum.