Monte Carlo Simulation Modeling of a Regional Stroke Team's Use of Telemedicine

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.

Impact of Telestroke Implementation on Emergency Department Transfer Rate

BACKGROUND

and Purpose: Telestroke networks are associated with improved outcomes from acute ischemic stroke(AIS) patient and facilitate greater access to care, particularly in underserved regions. These networks also have the potential to influence patient disposition through avoiding unnecessary interhospital transfers. This study examines the impact of implementation of the VA National Telestroke Program (NTSP) on interhospital transfer among Veterans.

METHODS

We analyzed AIS patients presenting to the emergency department 21 VA hospitals before and after telestroke implementation. Transfer rates were determined through review of administrative data and chart review and patient and facility level characteristics were collected to identify predictors of transfer. Comparisons were made using t-test, Wilcoxon rank sum, and chi-square analysis. Multivariable logistic regression with sensitivity analyses were conducted to assess the influence of telestroke implementation on transfer rates.

RESULTS

We analyzed 3,488 stroke encounters (1,056 pre-NTSP and 2,432 post-NTSP). Following implementation, we observed an absolute 14.4% decrease in transfers across all levels of stroke center designation. Younger age, higher stroke severity, and shorter duration from symptom onset were associated with transfer. At the facility level, hospitals with lower annual stroke volume were more likely to transfer although only one hospital actually saw an increase in transfer rates following implementation. After adjusting for patient and facility characteristics, the implementation of VA NTSP resulted in a nearly 60% reduction in odds of transfer (OR = 0.39, [0.19, 0.77]).

CONCLUSIONS

In addition to improving treatment in acute stroke, telestroke networks have the potential to positively impact the efficiency of interhospital networks through disposition optimization and the avoidance of unnecessary transfers.

Quantifying the Impact of Acute Stroke System of Care Transfer Protocols on Patient Outcomes

BACKGROUND

We quantify the impact of implementing a stroke system of care requiring transport of individuals believed to have stroke to a primary stroke center, in rural and urban settings, based on time from symptom recognition to treatment, probability of receiving treatment within 3 hours of stroke onset, and probability of overcrowding. We use Indiana as an example.

METHODS

We used discrete-event simulation to estimate outcomes for 2 scenarios: stroke system of care with enabling technology (mobile stroke unit, stroke team expansion) and stroke system of care with no enabling technology, as compared with the status quo. We considered patient flow from symptom recognition to treatment. Patient locations and stroke events were generated for the 92 Indiana counties in Indiana, subdivided into 1009 locations. We considered time from emergency medical service (EMS) arrival at onset to treatment, probability of tissue plasminogen activator administered within 3 h of onset, and percentage of patients admitted beyond the occupancy level at the comprehensive stroke center.

RESULTS

Results varied by urbanicity. Under no enabling technology, having a stroke system of care improved outcomes for individuals in urban and suburban settings. However, in rural settings, the implementation of stroke system of care guidelines decreased the average rate of treatment within 3 h of stroke onset and increased the EMS arrival to treatment times compared with sending the individual to the closest provider. Enabling technologies improved outcomes regardless of setting.

DISCUSSION

Geographic disparities tend to increase the number of transfers, decrease the rate of treatment within 3 h of onset, and increase transit time. This could be overcome through federal and state initiatives to reduce quality gaps in stroke care in rural settings and promote care with dedicated stroke wards.

Understanding Emergency Care Delivery Through Computer Simulation Modeling

In 2017, Academic Emergency Medicine convened a consensus conference entitled, "Catalyzing System Change through Health Care Simulation: Systems, Competency, and Outcomes." This article, a product of the breakout session on "understanding complex interactions through systems modeling," explores the role that computer simulation modeling can and should play in research and development of emergency care delivery systems. This article discusses areas central to the use of computer simulation modeling in emergency care research. The four central approaches to computer simulation modeling are described (Monte Carlo simulation, system dynamics modeling, discrete-event simulation, and agent-based simulation), along with problems amenable to their use and relevant examples to emergency care. Also discussed is an introduction to available software modeling platforms and how to explore their use for research, along with a research agenda for computer simulation modeling. Through this article, our goal is to enhance adoption of computer simulation, a set of methods that hold great promise in addressing emergency care organization and design challenges.

Modeling the Impact of Interhospital Transfer Network Design on Stroke Outcomes in a Large City

BACKGROUND AND PURPOSE

We sought to model the effects of interhospital transfer network design on endovascular therapy eligibility and clinical outcomes of stroke because of large-vessel occlusion for the residents of a large city.

METHODS

We modeled 3 transfer network designs for New York City. In model A, patients were transferred from spoke hospitals to the closest hub hospitals with endovascular capabilities irrespective of hospital affiliation. In model B, which was considered the base case, patients were transferred to the closest affiliated hub hospitals. In model C, patients were transferred to the closest affiliated hospitals, and transfer times were adjusted to reflect full implementation of streamlined transfer protocols. Using Monte Carlo methods, we simulated the distributions of endovascular therapy eligibility and good functional outcomes (modified Rankin Scale score, 0-2) in these models.

RESULTS

In our models, 200 patients (interquartile range [IQR], 168-227) with a stroke amenable to endovascular therapy present to New York City spoke hospitals each year. Transferring patients to the closest hub hospital irrespective of affiliation (model A) resulted in 4 (IQR, 1-9) additional patients being eligible for endovascular therapy and an additional 1 (IQR, 0-2) patient achieving functional independence. Transferring patients only to affiliated hospitals while simulating full implementation of streamlined transfer protocols (model C) resulted in 17 (IQR, 3-41) additional patients being eligible for endovascular therapy and 3 (IQR, 1-8) additional patients achieving functional independence.

CONCLUSIONS

Optimizing acute stroke transfer networks resulted in clinically small changes in population-level stroke outcomes in a dense, urban area.