Primary Stroke Centers Should Be Located Using Maximal Coverage Models for Optimal Access

The Role of the Vascular Neurologist in Optimizing Stroke Care

The article summarizes the training pathways and vocational opportunities within the field of vascular neurology. It highlights the groundbreaking clinical trials that transformed acute stroke care and the resultant increased demand for readily available vascular neurology expertise. The article emphasizes the need to train a larger number of diverse physicians in the subspecialty and the role of vascular neurologists in improving outcomes across demographic and geographic lines.

The Capacitated Maximal Covering Location Problem Improves Access to Stroke Treatment: A Cross-Sectional Simulation Study

Disparities in accessing advanced stroke treatment have been recognized as a policy challenge in multiple countries, including Japan, necessitating priority solutions. Nevertheless, more practical healthcare policies must be implemented due to the limited availability of healthcare staff and financial resources in most nations. This study aimed to evaluate the supply and demand balance of mechanical thrombectomy (MT) and identify areas with high priority for enhancing stroke centers. The target area of this study was Hokkaido, Japan. We adopted the capacitated maximal covering location problem (CMCLP) to propose an optimal allocation without increasing the number of medical facilities. Four realistic scenarios with varying levels of total MT supply capacity for Primary stroke centers and assuming a range of 90 minutes by car from the center were created and simulated. From scenarios 1 to 4, the coverage increased by approximately 53% to 85%, scenarios 2 and 3 had 5% oversupply, and scenario 4 had an oversupply of approximately 20%. When the supply capacity cap was eliminated and 8 PSCs received 31 or more patients, they became priority enhancement targets. The CMCLP estimates demand coverage considering the supply and demand balance and indicates areas and facilities where MT supply capacity enhancement is a priority.

Improving urban emergency medical service systems through brownfield transformation in Huangshi, China

A comprehensive emergency medical service (EMS) system significantly enhances a city's capacity to prevent and mitigate disasters. Using Huangshi as a case study, this research evaluated the service radium coverage rate of the current EMS system by examining its transport capacity, population density, and prevalence rate, finding it to be only 61.49% with an inefficient spatial layout. To address this, we proposed transforming urban brownfields into EMS parks. By selecting the most suitable brownfields based on capacity and service radius, we increased the coverage rate to 90.21%. We introduced a new "consultation-referral" model, where existing EMS facilities serve as pre-diagnosis and triage centers, and the urban brownfield EMS parks function as isolation and centralized treatment centers. GIS network analysis confirmed the feasibility, showing all transit times to be under 30 min. The methodology outlined in this study-comprising "demand assessment, supply optimization, and feasibility verification"-not only strengthens the city's EMS system but also facilitates the renewal of urban brownfields. This approach can serve as a valuable reference for enhancing EMS systems in other cities.

Optimization of the stroke hospital selection strategy and the distribution of endovascular thrombectomy resources

Nowadays, emergency medical technicians (EMTs) decide to send a suspected stroke patient to a primary stroke center (PSC) or to an endovascular thrombectomy (EVT)-capable hospital, based on the Cincinnati Prehospital Stroke Scale (CPSS) and the number of symptoms a patient presents at the scene. Based on existing studies, the patient is likely to have a better functional outcome after three months if the time between the onset of symptoms and receiving EVT treatment is shorter. However, if an acute ischemic stroke (AIS) patient with large vessel occlusion (LVO) is first sent to a PSC, and then needs to be transferred to an EVT-capable hospital, the time to get definitive treatment is significantly increased. For this purpose, We formulate an integer programming model to minimize the expected time to receive a definitive treatment for stroke patients. We then use real-world data to verify the validity of the model. Also, we expand our model to find the optimal redistribution and centralization of EVT resources. It will enable therapeutic teams to increase their experience and skills more efficiently within a short period of time.

Spatial-temporal analysis of cerebral infarction mortality in Hokkaido, Japan: an ecological study using a conditional autoregressive model

BACKGROUND

Accessibility to stroke treatments is a challenge that depends on the place of residence. However, recent advances in medical technology have improved health outcomes. Nevertheless, the geographic heterogeneity of medical resources may increase regional disparities. Therefore, evaluating spatial and temporal influences of the medical system on regional outcomes and advanced treatment of cerebral infarction are important from a health policy perspective. This spatial and temporal study aims to identify factors associated with mortality and to clarify regional disparities in cerebral infarction mortality at municipality level.

METHODS

This ecological study used public data between 2010 and 2020 from municipalities in Hokkaido, Japan. We applied spatial and temporal condition autoregression analysis in a Bayesian setting, with inference based on the Markov chain Monte Carlo simulation. The response variable was the number of deaths due to cerebral infarction (ICD-10 code: I63). The explanatory variables were healthcare accessibility and socioeconomic status.

RESULTS

The large number of emergency hospitals per 10,000 people (relative risk (RR) = 0.906, credible interval (Cr) = 0.861 to 0.954) was associated with low mortality. On the other hand, the large number of general hospitals per 10,000 people (RR = 1.123, Cr = 1.068 to 1.178) and longer distance to primary stroke centers (RR = 1.064, Cr = 1.014 to 1.110) were associated with high mortality. The standardized mortality ratio decreased from 2010 to 2020 in Hokkaido by approximately 44%. Regional disparity in mortality remained at the same level from 2010 to 2015, after which it narrowed by approximately 5% to 2020. After mapping, we identified municipalities with high mortality rates that emerged in Hokkaido's central and northeastern parts.

CONCLUSION

Cerebral infarction mortality rates and the disparity in Hokkaido improved during the study period (2010-2020). This study emphasized that healthcare accessibility through places such as emergency hospitals and primary stroke centers was important in determining cerebral infarction mortality at the municipality level. In addition, this study identified municipalities with high mortality rates that require healthcare policy changes. The impact of socioeconomic factors on stroke is a global challenge, and improving access to healthcare may reduce disparities in outcomes.

Structural Inequities for Historically Underserved Communities in the Adoption of Stroke Certification in the United States

Importance

Stroke centers are associated with better outcomes. There is substantial literature surrounding disparities in stroke outcomes for underserved populations. However, the existing literature has focused primarily on discrimination at the individual or institutional level, and studies of structural discrimination in stroke care are scant.

Objective

To examine differences in hospitals' likelihood of adopting stroke care certification between historically underserved and general communities.

Design, Setting, and Participants

This study combined a data set of hospital stroke certification from all general acute nonfederal hospitals in the continental US from January 1, 2009, to December 31, 2019, with national, hospital, and census data to define historically underserved communities by racial and ethnic composition, income distribution, and rurality. For all categories except rurality, communities were categorized by the composition and degree of segregation of each characteristic. Cox proportional hazard models were then estimated to compare the hazard of adopting stroke care certification between historically underserved and general communities, adjusting for population size and hospital bed capacity. Data were analyzed from June 2021 to April 2022.

Main Outcomes and Measures

Hospitals' likelihood of adopting stroke care certification.

Results

A total of 4984 hospitals were included. From 2009 to 2019, the total number of hospitals with stroke certification grew from 961 to 1763. Hospitals serving Black, racially segregated communities had the highest hazard of adopting stroke care certification (hazard ratio [HR], 1.67; 95% CI, 1.41-1.97) in models not accounting for population size, but their hazard was 26% lower than among those serving non-Black, racially segregated communities (HR, 0.74; 95% CI, 0.62-0.89) in models controlling for population and hospital size. Adoption hazard was lower in low-income communities compared with high-income communities, regardless of their level of economic segregation, and rural hospitals were much less likely to adopt any level of stroke care certification relative to urban hospitals (HR, 0.43; 95% CI, 0.35-0.51).

Conclusions and Relevance

In this analysis of stroke certification adoption across acute care hospitals in the US from 2009 to 2019, hospitals in low-income and rural communities had a lower likelihood of receiving stroke certification than hospitals in general communities. Hospitals operating in Black, racially segregated communities had the highest likelihood of adopting stroke care, but because these communities had the largest population, patients in these communities had the lowest likelihood of access to stroke-certified hospitals when the model controlled for population size. These findings provide empirical evidence that the provision of acute neurological services is structurally inequitable across historically underserved communities.

Concept review of regionalized systems of acute care: Is regionalization the next frontier in sepsis care?

Regionalization has become a buzzword in US health care policy. Regionalization, however, has varied meanings, and definitions have lacked contextual information important to understanding its role in improving care. This concept review is a comprehensive primer and summation of 8 common core components of the national models of regionalization informed by text-based analysis of the writing of involved organizations (professional, regulatory, and research) guided by semistructured interviews with organizational leaders. Further, this generalized model of regionalized care is applied to sepsis care, a novel discussion, drawing on existing small-scale applications. This discussion highlights the fit of regionalization principles to the sepsis care model and the actualized and perceived potential benefits. The principal aim of this concept review is to outline regionalization in the United States and provide a roadmap and novel discussion of regionalized care integration for sepsis care.

Equity of geographical access to public health facilities in Nepal

Introduction

Geographical accessibility is important against health equity, particularly for less developed countries as Nepal. It is important to identify the disparities in geographical accessibility to the three levels of public health facilities across Nepal, which has not been available.

Methods

Based on the up-to-date dataset of Nepal formal public health facilities in 2021, we measured the geographical accessibility by calculating the travel time to the nearest public health facility of three levels (ie, primary, secondary and tertiary) across Nepal at 1×1 km² resolution under two travel modes: walking and motorised. Gini and Theil L index were used to assess the inequality. Potential locations of new facilities were identified for best improvement of geographical efficiency or equality.

Results

Both geographical accessibility and its equality were better under the motorised mode compared with the walking mode. If motorised transportation is available to everyone, the population coverage within 5 min to any public health facilities would be improved by 62.13%. The population-weighted average travel time was 17.91 min, 39.88 min and 69.23 min and the Gini coefficients 0.03, 0.18 and 0.42 to the nearest primary, secondary and tertiary facilities, respectively, under motorised mode. For primary facilities, low accessibility was found in the northern mountain belt; for secondary facilities, the accessibility decreased with increased distance from the district centres; and for tertiary facilities, low accessibility was found in most areas except the developed areas like zonal centres. The potential locations of new facilities differed for the three levels of facilities. Besides, the majority of inequalities of geographical accessibility were from within-province.

Conclusion

The high-resolution geographical accessibility maps and the assessment of inequality provide valuable information for health resource allocation and health-related planning in Nepal.

Expanding resources of endovascular thrombectomy: An optimization model

BACKGROUND/PURPOSE

Recently optimized models for selecting the locations of hospitals capable of providing endovascular thrombectomy (EVT) did not consider the accuracy of the prehospital stroke scale assessment and possibility of secondary transport. Our study aimed to propose a new model for selecting existing hospitals with intravenous thrombolysis capability to become EVT-capable hospitals.

METHODS

A sequential order was provided to upgrade hospitals providing intravenous thrombolysis, using a mixed integer programming model based on current medical resource allocation. In addition, we drafted a centralized plan to redistribute existing EVT resources by redetermining locations of EVT-capable hospitals. Using historical data of 7679 on-scene patients with suspected stroke, the model was implemented to determine the hospital that maximizes the number of patients receiving EVT treatment within call-to-definitive-treatment time.

RESULTS

All suspected stroke patients were sent to EVT-capable hospitals directly under the current medical resource allocation model. After upgrading one additional hospital to become an EVT-capable hospital, the percentage of patients receiving definitive treatment within the standard call-to-definitive-treatment time was elevated from 68.82% to 72.97%. In the model, assuming that there is no hospital providing EVT, all patients suspected of stroke will be sent to EVT-capable hospitals directly after upgrading three or more hospitals to be able to provide treatment.

CONCLUSION

All patients eligible for acute stroke treatment are sent to EVT-capable hospitals in the simulation under the current medical resource allocation model. This model can be utilized to provide insights for capacity redistribution in other regions.

Spatial analysis of service areas for stroke centers in a city with high traffic congestion

The effect that traffic congestion has on the service areas of stroke centers has received scarce attention. We aimed to determine the effect of traffic conditions on the characteristics of service areas of stroke centers in Bogotá, Colombia. Using a webservice, we sampled travel times from a set of census blocks to medical centers offering stroke management in the city. We obtained 179.340 transport times under different conditions. The size of service areas was reduced significantly with congestion (up to 94.83%). Overlap in the locations of centers led to large areas covered by only five centers. We identified areas with transport times to the closest center consistently exceeding 30-minutes to 1-hour in the west and south-west. Traffic conditions in Bogotá significantly affect service areas of centers capable of offering comprehensive stroke care. Spatial overlap of centers led to small catchment areas.

Using spatially adaptive floating catchments to measure the geographic availability of a health care service: Pulmonary rehabilitation in the southeastern United States

A spatially adaptive floating catchment is a circular area that expands outward from a provider location until the estimated demand for services in the nearest population locations exceeds the observed number of health care services performed at the provider location. This new way of creating floating catchments was developed to address the change of spatial support problem (COSP) by upscaling the availability of the service observed at a provider location to the county-level so that its geographic association with utilization could be measured using the same spatial support. Medicare Fee-for-Service claims data were used to identify beneficiaries aged ≥ 65 years who received outpatient pulmonary rehabilitation (PR) in the Southeastern United States in 2014 (n = 8798), the number of PR treatments these beneficiaries received (n = 132,508), and the PR providers they chose (n = 426). The positive correlation between PR availability and utilization was relatively low, but statistically significant (r = 0.619, p < 0.001) indicating that most people use the nearest available PR services, but some travel long distances. SAFCs can be created using data from health care systems that collect claim-level utilization data that identifies the locations of providers chosen by beneficiaries of a specific health care procedure.

Early Recovery of Aphasia through Thrombolysis: The Significance of Spontaneous Speech

BACKGROUND

Aphasia is one of the most devastating stroke-related consequences for social interaction and daily activities. Aphasia recovery in acute stroke depends on the degree of reperfusion after thrombolysis or thrombectomy. As aphasia assessment tests are often time-consuming for patients with acute stroke, physicians have been developing rapid and simple tests. The aim of our study is to evaluate the improvement of language functions in the earliest stage in patients treated with thrombolysis and in nontreated patients using our rapid screening test.

MATERIALS AND METHODS

Our study is a single-center prospective observational study conducted at the Stroke Unit of the University Medical Hospital of Trieste (January-December 2016). Patients treated with thrombolysis and nontreated patients underwent 3 aphasia assessments through our rapid screening test (at baseline, 24 hours, and 72 hours). The screening test assesses spontaneous speech, oral comprehension of words, reading aloud and comprehension of written words, oral comprehension of sentences, naming, repetition of words and a sentence, and writing words.

RESULTS

The study included 40 patients: 18 patients treated with thrombolysis and 22 nontreated patients. Both groups improved over time. Among all language parameters, spontaneous speech was statistically significant between 24 and 72 hours (P value = .012), and between baseline and 72 hours (P value = .017).

CONCLUSIONS

Our study demonstrates that patients treated with thrombolysis experience greater improvement in language than the nontreated patients. The difference between the 2 groups is increasingly evident over time. Moreover, spontaneous speech is the parameter marked by the greatest improvement.

Effect of patient choice and hospital competition on service configuration and technology adoption within cancer surgery: a national, population-based study

Background

There is a scarcity of evidence about the role of patient choice and hospital competition policies on surgical cancer services. Previous evidence has shown that patients are prepared to bypass their nearest cancer centre to receive surgery at more distant centres that better meet their needs. In this national, population-based study we investigated the effect of patient mobility and hospital competition on service configuration and technology adoption in the National Health Service (NHS) in England, using prostate cancer surgery as a model.

Methods

We mapped all patients in England who underwent radical prostatectomy between Jan 1, 2010, and Dec 31, 2014, according to place of residence and treatment location. For each radical prostatectomy centre we analysed the effect of hospital competition (measured by use of a spatial competition index [SCI], with a score of 0 indicating weakest competition and 1 indicating strongest competition) and the effect of being an established robotic radical prostatectomy centre at the start of 2010 on net gains or losses of patients (difference between number of patients treated in a centre and number expected based on their residence), and the likelihood of closing their radical prostatectomy service.

Findings

Between Jan 1, 2010, and Dec 31, 2014, 19 256 patients underwent radical prostatectomy at an NHS provider in England. Of the 65 radical prostatectomy centres open at the start of the study period, 23 (35%) had a statistically significant net gain of patients during 2010–14. Ten (40%) of these 23 were established robotic centres. 37 (57%) of the 65 centres had a significant net loss of patients, of which two (5%) were established robotic centres and ten (27%) closed their radical prostatectomy service during the study period. Radical prostatectomy centres that closed were more likely to be located in areas with stronger competition (highest SCI quartile [0·87–0·92]; p=0·0081) than in areas with weaker competition. No robotic surgery centre closed irrespective of the size of net losses of patients. The number of centres performing robotic surgery increased from 12 (18%) of the 65 centres at the beginning of 2010 to 39 (71%) of 55 centres open at the end of 2014.

Interpretation

Competitive factors, in addition to policies advocating centralisation and the requirement to do minimum numbers of surgical procedures, have contributed to large-scale investment in equipment for robotic surgery without evidence of superior outcomes and contributed to the closure of cancer surgery units. If quality performance and outcome indicators are not available to guide patient choice, these policies could threaten health services' ability to deliver equitable and affordable cancer care.

Funding

National Institute for Health Research.

Primary Stroke Center Hospitalization for Elderly Patients With Stroke: Implications for Case Fatality and Travel Times

IMPORTANCE

Physicians often must decide whether to treat patients with acute stroke locally or refer them to a more distant Primary Stroke Center (PSC). There is little evidence on how much the increased risk of prolonged travel time offsets benefits of a specialized PSC care.

OBJECTIVES

To examine the association of case fatality with receiving care in PSCs vs other hospitals for patients with stroke and to identify whether prolonged travel time offsets the effect of PSCs.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study of Medicare beneficiaries with stroke admitted to a hospital between January 1, 2010, and December 31, 2013. Drive times were calculated based on zip code centroids and street-level road network data. We used an instrumental variable analysis based on the differential travel time to PSCs to control for unmeasured confounding. The setting was a 100% sample of Medicare fee-for-service claims.

EXPOSURES

Admission to a PSC.

MAIN OUTCOMES AND MEASURES

Seven-day and 30-day postadmission case-fatality rates.

RESULTS

Among 865 184 elderly patients with stroke (mean age, 78.9 years; 55.5% female), 53.9% were treated in PSCs. We found that admission to PSCs was associated with 1.8% (95% CI, -2.1% to -1.4%) lower 7-day and 1.8% (95% CI, -2.3% to -1.4%) lower 30-day case fatality. Fifty-six patients with stroke needed to be treated in PSCs to save one life at 30 days. Receiving treatment in PSCs was associated with a 30-day survival benefit for patients traveling less than 90 minutes, but traveling at least 90 minutes offset any benefit of PSC care.

CONCLUSIONS AND RELEVANCE

Hospitalization of patients with stroke in PSCs was associated with decreased 7-day and 30-day case fatality compared with noncertified hospitals. Traveling at least 90 minutes to receive care offset the 30-day survival benefit of PSC admission.

Effectiveness of regionalized systems for stroke and myocardial infarction

BACKGROUND

Acute ischemic stroke (AIS) and ST-segment elevation myocardial infarction (STEMI) are ischemic emergencies. Guidelines recommend care delivery within formally regionalized systems of care at designated centers, with bypass of nearby centers of lesser or no designation. We review the evidence of the effectiveness of regionalized systems in AIS and STEMI.

METHODS

Literature was searched using terms corresponding to designation of AIS and STEMI systems and from 2010 to the present. Inclusion criteria included report of an outcome on any dependent variable mentioned in the rationale for regionalization in the guidelines and an independent variable comparing care to a non- or pre-regionalized system. Designation was defined in the AIS case as certification by the Joint Commission as either a primary (PSC) or comprehensive (CSC) stroke center. In the STEMI case, the search was conducted linking "regionalization" and "myocardial infarction" or citation as a model system by any American Heart Association statement.

RESULTS

For AIS, 17 publications met these criteria and were selected for review. In the STEMI case, four publications met these criteria; the search was therefore expanded by relaxing the criteria to include any historical or anecdotal comparison to a pre- or nonregionalized state. The final yield was nine papers from six systems.

CONCLUSION

Although regionalized care results in enhanced process and reduced unadjusted rates of disparity in access and adverse outcomes, these differences tend to become nonsignificant when adjusted for delayed presentation and hospital arrival by means other than emergency medical services. The benefits of regionalized care occur along with a temporal trend of improvement due to uptake of quality initiatives and guideline recommendations by all systems regardless of designation. Further research is justified with a randomized registry or cluster randomized design to support or refute recommendations that regionalization should be the standard of care.

Discrete event simulation of patient admissions to a neurovascular unit

Evidence exists that clinical outcomes improve for stroke patients admitted to specialized Stroke Units. The Toronto Western Hospital created a Neurovascular Unit (NVU) using beds from general internal medicine, Neurology and Neurosurgery to care for patients with stroke and acute neurovascular conditions. Using patient-level data for NVU-eligible patients, a discrete event simulation was created to study changes in patient flow and length of stay pre- and post-NVU implementation. Varying patient volumes and resources were tested to determine the ideal number of beds under various conditions. In the first year of operation, the NVU admitted 507 patients, over 66% of NVU-eligible patient volumes. With the introduction of the NVU, length of stay decreased by around 8%. Scenario testing showed that the current level of 20 beds is sufficient for accommodating the current demand and would continue to be sufficient with an increase in demand of up to 20%.

How many suffice? A computational framework for sizing sentinel surveillance networks

Background

Data from surveillance networks help epidemiologists and public health officials detect emerging diseases, conduct outbreak investigations, manage epidemics, and better understand the mechanics of a particular disease. Surveillance networks are used to determine outbreak intensity (i.e., disease burden) and outbreak timing (i.e., the start, peak, and end of the epidemic), as well as outbreak location. Networks can be tuned to preferentially perform these tasks. Given that resources are limited, careful site selection can save costs while minimizing performance loss.

Methods

We study three different site placement algorithms: two algorithms based on the maximal coverage model and one based on the K-median model. The maximal coverage model chooses sites that maximize the total number of people within a specified distance of a site. The K-median model minimizes the sum of the distances from each individual to the individual’s nearest site. Using a ground truth dataset consisting of two million de-identified Medicaid billing records representing eight complete influenza seasons and an evaluation function based on the Huff spatial interaction model, we empirically compare networks against the existing Iowa Department of Public Health influenza-like illness network by simulating the spread of influenza across the state of Iowa.

Results

We show that it is possible to design a network that achieves outbreak intensity performance identical to the status quo network using two fewer sites. We also show that if outbreak timing detection is of primary interest, it is actually possible to create a network that matches the existing network’s performance using 59% fewer sites.

Conclusions

By simulating the spread of influenza across the state of Iowa, we show that our methods are capable of designing networks that perform better than the status quo in terms of both outbreak intensity and timing. Additionally, our results suggest that network size may only play a minimal role in outbreak timing detection. Finally, we show that it may be possible to reduce the size of a surveillance system without affecting the quality of surveillance information produced.

Disparities in evaluation at certified primary stroke centers: reasons for geographic and racial differences in stroke

BACKGROUND AND PURPOSE

Evaluation at primary stroke centers (PSCs) has the potential to improve outcomes for patients with stroke. We looked for differences in evaluation at Joint Commission certified PSCs by race, education, income, and geography (urban versus nonurban; Southeastern Stroke Belt versus non-Stroke Belt).

METHODS

Community-dwelling, black and white participants from the national Reasons for Geographic And Racial Differences in Stroke (REGARDS) prospective population-based cohort were enrolled between January 2003 and October 2007. Participants were contacted at 6-month intervals for suspected stroke events. For suspected stroke events, it was determined whether the evaluating hospital was a certified PSC.

RESULTS

Of 1000 suspected strokes, 204 (20.4%) strokes were evaluated at a PSC. A smaller proportion of women than men (17.8% versus 23.0%; P=0.04), those with a previous stroke (15.1% versus 21.6%; P=0.04), those living in the Stroke Belt (14.7% versus 27.3%; P<0.001), and those in a nonurban area (9.1% versus 23.1%; P<0.001) were evaluated at a PSC. There were no differences by race, education, or income. In multivariable analysis, subjects were less likely to be evaluated at a PSC if they lived in a nonurban area (odds ratio, 0.39; 95% confidence interval, 0.22-0.67) or lived in the Stroke Belt (odds ratio, 0.54; 95% confidence interval, 0.38-0.77) or had a previous stroke (odds ratio, 0.46; 95% confidence interval, 0.27-0.78).

CONCLUSIONS

Disparities in evaluation by PSCs are predominately related to geographic factors but not to race, education, or low income. Despite an increased burden of cerebrovascular disease in the Stroke Belt, subjects there were less likely to be evaluated at certified hospitals.