Hospital Volume and Mortality in Acute Ischemic Stroke Patients: Effect of Adjustment for Stroke Severity

Network analysis of stroke systems of care in Korea

Background

The landscape of stroke care has shifted from stand-alone hospitals to cooperative networks among hospitals. Despite the importance of these networks, limited information exists on their characteristics and functional attributes.

Methods

We extracted patient-level data on acute stroke care and hospital connectivity by integrating national stroke audit data with reimbursement claims data. We then used this information to transform interhospital transfers into a network framework, where hospitals were designated as nodes and transfers as edges. Using the Louvain algorithm, we grouped densely connected hospitals into distinct stroke care communities. The quality and characteristics in given stroke communities were analysed, and their distinct types were derived using network parameters. The clinical implications of this network model were also explored.

Results

Over 6 months, 19 113 patients with acute ischaemic stroke initially presented to 1009 hospitals, with 3114 (16.3%) transferred to 246 stroke care hospitals. These connected hospitals formed 93 communities, with a median of 9 hospitals treating a median of 201 patients. Derived communities demonstrated a modularity of 0.904 , indicating a strong community structure, highly centralised around one or two hubs. Three distinct types of structures were identified: single-hub (n=60), double-hub (n=22) and hubless systems (n=11). The endovascular treatment rate was highest in double-hub systems, followed by single-hub systems, and was almost zero in hubless systems. The hubless communities were characterised by lower patient volumes, fewer hospitals, no hub hospital and no stroke unit.

Conclusions

This network analysis could quantify the national stroke care system and point out areas where the organisation and functionality of acute stroke care could be improved.

2024 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2024 AHA Statistical Update is the product of a full year's worth of effort in 2023 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. The AHA strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional global data, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Relationships among hospital acute ischemic stroke volumes, hospital characteristics, and outcomes in the US

BACKGROUND AND OBJECTIVES

Prior research on volume-based patient outcomes related to acute ischemic stroke (AIS) have demonstrated contradictory results and fail to reflect recent advances in stroke care. We sought to examine contemporary relationships between hospital AIS volumes and outcomes.

METHODS

We used complete Medicare datasets in a retrospective cohort study using validated International Classification of Diseases Tenth Revision codes to identify patients admitted with AIS from January 1, 2016 through December 31, 2019. AIS volume was calculated as the total number of AIS admissions per hospital during the study period. We examined several hospital characteristics by AIS volume quartile. We performed adjusted logistic regressions testing associations of AIS volume quartiles with: inpatient mortality, receipt of tissue plasminogen activator (tPA) and endovascular therapy (ET), discharge home, and 30-day outpatient visit. We adjusted for sex, age, Charlson comorbidity score, teaching hospital status, MDI, hospital urban-rural designation, stroke certification status and ICU and neurologist availability at the hospital.

RESULTS

There were 952400 AIS admissions among 5084 US hospitals; AIS 4-year volume quartiles were: 1^st: 1-8 AIS admissions; 2^nd: 9-44; 3^rd: 45-237; 4^th: 238+. Highest quartile hospitals more often were stroke-certified (49.1% vs 8.7% in lowest quartile, p<0.0001), with ICU bed availability (19.8% vs 4.1%, p<0.0001) and with neurologist expertise (91.1% vs 3%, p<0.0001). In the highest AIS quartile (compared to the lowest quartile), there was lower inpatient mortality (odds ratio [OR] 0.71 [95%CI 0.57-0.87, p<0.0001]), lower 30-day mortality (0.55 [0.49-0.62], p<0.0001), greater receipt of tPA (6.60 [3.19-13.65], p<0.0001) and ET (16.43 [10.64-25.37], p<0.0001, and greater likelihood of discharge home (1.38 [1.22-1.56], p<0.0001). However, when the highest quartile hospitals were examined separately, higher volumes were associated with higher mortality despite higher rates of tPA and ET receipt.

CONCLUSIONS

High AIS-volume hospitals have greater utilization of acute stroke interventions, stroke certification and availability of neurologist and ICU care. These features likely play a role in the better outcomes observed at such centers, including inpatient and 30-day mortality and discharge home. However, the highest volume centers had higher mortality despite greater receipt of interventions. Further research is needed to better understand volume-outcome relationships in AIS to improve care at lower volume centers.

Heart Disease and Stroke Statistics-2023 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2023 Statistical Update is the product of a full year's worth of effort in 2022 by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. The American Heart Association strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional COVID-19 (coronavirus disease 2019) publications, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Understanding the Influence of Hospital Volume on Inpatient Outcomes Following Hospitalization for Status Epilepticus

BACKGROUND

Prior studies show hospital admission volume to be associated with poor outcomes following elective procedures and inpatient medical hospitalizations. However, it is unknown whether hospital volume impacts Inpatient outcomes for status epilepticus (SE) hospitalizations. In this study, we aimed to assess the impact of hospital volume on the outcome of patients with SE and related inpatient medical complications.

METHODS

The 2005 to 2013 National Inpatient Sample database was queried using International Classification of Diseases 9th Edition diagnosis code 345.3 to identify patients undergoing acute hospitalization for SE. The National Inpatient Sample hospital identifier was used as a unique facility identifier to calculate the average volume of patients with SE seen in a year. The study cohort was divided into three groups: low volume (0-7 patients with SE per year), medium volume (8-22 patients with SE per year), and high volume (> 22 patients with SE per year). Multivariate logistic regression analyses were used to assess whether medium or high hospital volume had lower rates of inpatient medical complications compared with low-volume hospitals.

RESULTS

A total of 137,410 patients with SE were included in the analysis. Most patients (n = 50,939; 37%) were treated in a low-volume hospital, 31% (n = 42,724) were treated in a medium-volume facility, and 18% (n = 25,207) were treated in a high-volume hospital. Patients undergoing treatment at medium-volume hospitals (vs. low-volume hospitals) had higher odds of pulmonary complications (odds ratio [OR] 1.18 [95% confidence interval {CI} 1.12-1.25]; p < 0.001), sepsis (OR 1.24 [95% CI 1.08-1.43] p = 0.002), and length of stay (OR 1.13 [95% CI 1.0 -1.19] p < 0.001). High-volume hospitals had significantly higher odds of urinary tract infections (OR 1.21 [95% CI 1.11-1.33] p < 0.001), pulmonary complications (OR 1.19 [95% CI 1.10-1.28], p < 0.001), thrombosis (OR 2.13 [95% CI 1.44-3.14], p < 0.001), and renal complications (OR 1.21 [95% CI 1.07-1.37], p = 0.002). In addition, high-volume hospitals had lower odds of metabolic (OR 0.81 [95% CI 0.72-0.91], p < 0.001), neurological complications (OR 0.80 [95% CI 0.69-0.93], p = 0.004), and disposition to a facility (OR 0.89 [95% CI 0.82-0.96], p < 0.001) compared with lower-volume hospitals.

CONCLUSIONS

Our study demonstrates certain associations between hospital volume and outcomes for SE hospitalizations. Further studies using more granular data about the type, severity, and duration of SE and types of treatment are warranted to better understand how hospital volume may impact care and prognosis of patients.

Association between volume of patients undergoing stroke rehabilitation at acute care hospitals and improvement in activities of daily living

BACKGROUND

This study aimed to determine the relationship between the annual volume of patients undergoing rehabilitation per hospital and the outcomes of patients admitted for acute stroke.

METHODS

This observational study used nationwide administrative data. Data on stroke patients aged ≥ 20 years who underwent rehabilitation were extracted from 1,182 acute care hospitals in Japan. The exclusion criteria were extended hospital stay exceeding 180 days and death during hospitalization. Hospital volumes were divided into four quartiles of total patients per hospital. The primary outcome was an improvement in activities of daily living from admission to discharge measured using the Barthel index. Poisson regression analysis of activities of daily living improvement was performed using inverse probability of treatment weighting.

RESULTS

High rehabilitation volume was significantly correlated with improvements in activities of daily living using the "very low group" as a reference (risk ratio [95% confidence interval]): 1.06 [1.05-1.08], P<0.001). Low volume was also significantly associated with activities of daily living improvement (risk ratio [95% confidence interval]: 1.04 [1.03-1.06], P<0.001).

CONCLUSIONS

The annual volume of stroke patients undergoing multidisciplinary rehabilitation at a specific hospital may be a factor in the degree of patient improvement in activities of daily living.

Hospital size, remoteness and stroke outcome

INTRODUCTION

Previous studies have shown an association between number of stroke admissions and outcomes. Small hospitals often support more remote areas and we studied national data to determine if an association exists between hospital remoteness and stroke care.

METHODS

Data from the Irish National Audit of Stroke (INAS) on average stroke admissions, adjusted mortality for Ischaemic stroke, thrombolysis rate and proportion with door to needle (DTN) ≤45 minutes were analyzed. Hospital remoteness was quantified by distance to the next hospital, nearest neuro-interventional centre and location within 10 km of the national motorway network.

RESULTS

Data for all 23 of 24 Stroke services were evaluated. Median number of strokes admitted per year was 186 (range 84 to 497). Nine hospitals (39%) admitted ≥200 stroke patients per year (mean 332). Average adjusted mortality (7.0 vs 7.3, p = 0.67 t-test), mean thrombolysis rate (12.1% vs. 9.2% p = 0.09) and mean proportion of patients treated ≤45 minutes (40.4% vs 31.3%, p = 0.2) did not differ significantly between higher and lower volume hospitalsHospitals close to the motorway network (n = 15) had a higher mean thrombolysis rate (11.9% vs 7.5% p = 0.01 t-test) and proportion door to needle ≤45 mins (43.7%-18.4% p < 0.001).Number of stroke admissions did not correlate with mortality (r = 0.06 p = 0.78), or door to needle (r = 0.12 p = 0.95) or thrombolysis rate (r = 0.35 p = 0.20). Distance to next hospital correlated strongly negatively with DTN (r=-0.47, p = 0.02) and thrombolysis rate (-0.43, p = 0.04).

CONCLUSION

Remoteness of hospitals is associated with worse measures of stroke outcome and management.

Variation in stroke care at the hospital level: A cross-sectional multicenter study

Introduction

Stroke is one of the leading causes of mortality and disability. Improving patient outcomes can be achieved by improving stroke care and adherence to guidelines. Since wide variation in adherence rates for stroke guidelines still exists, we aimed to describe and compare stroke care variability within Belgian hospitals.

Materials and methods

An observational, multicenter study was performed in 29 Belgian hospitals. We retrospectively collected patient characteristics, quality indicators, and time metrics from the last 30 consecutive patients per hospital, diagnosed with ischemic stroke in 2019 with structured questionnaires. Mean adherence ratios (%) ± SD (minimum – maximum) were calculated.

Results

We analyzed 870 patient records from 29 hospitals. Results showed large inter- and intrahospitals variations in adherence for various indicators. Almost all the patients received brain imaging (99.7%) followed by admission at a stroke unit in 82.9% of patients. Of patients not receiving thrombolysis, 92.5% of patients were started on antithrombotic drugs. Indicators with moderate median adherence but large interhospital variability were glycemia monitoring [82.3 ± 16.7% (26.7–100.0%)], performing clinical neurological examination and documentation of stroke severity [63.1 ± 36.8% (0–100%)], and screening for activities of daily living [51.1 ± 40.3% (0.0–100.0%)]. Other indicators lacked adequate adherence: swallowing function screening [37.0 ± 30.4% (0.0–93.3%)], depression screening [20.2 ± 35.8% (0.0–100%)], and timely body temperature measurement [15.1 ± 17.0% (0.0–60%)].

Conclusion

We identified high adherence to guidelines for some indicators, but lower rates with large interhospital variability for other recommendations also based on robust evidence. Improvement strategies should be implemented to improve the latter.

Association between hospital volume, processes of care and outcomes after acute ischaemic stroke: a prospective observational study

OBJECTIVES

There is uncertainty with respect to the hospital volume and clinical outcomes for patients with stroke. This study aimed to assess the association between hospital volume, processes of care and outcomes after ischaemic stroke.

DESIGN

A multicentre prospective cohort study.

SETTING

Two hundred and seventeen secondary or tertiary public hospitals from China.

PARTICIPANTS

A total of 17 550 patients within 7 days of acute ischaemic stroke were included.

MAIN OUTCOME MEASURES

The outcomes included all-cause mortality, poor outcome, recurrent stroke, and combined vascular events at 3 months and 1 year. The patients were divided into four groups based on quartiles of the hospital volume. We compared the difference in the process of care across the groups and estimated the effects of hospital volume on mortality, poor outcome, recurrent stroke, and combined vascular events at 3 months and 1 year. Restricted cubic splines were used to illustrate the association between hospital volume and clinical outcomes.

RESULTS

There were no significant differences in the process of care across the four groups. When adjusted for confounders, the effect of hospital volume on mortality, recurrent stroke and combined vascular events was not significant. However, compared with the highest quartile, the patients in the lowest quartile of hospital volume tend to have poor outcome at 1 year (OR=1.29, 95% CI 1.01 to 1.64, p=0.0393). The restricted cubic spline analyses suggested a non-linear relationship between hospital volume and 1-year combined vascular events and poor outcome at 3 months and 1 year.

CONCLUSIONS

We found no significant associations between hospital volume, processes of care at the hospital, and mortality, recurrent stroke, and combined vascular events in patients with ischaemic stroke. However, hospital volume may be associated with poor outcome at 1 year.

Heart Disease and Stroke Statistics-2022 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2022 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population and an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, and the global burden of cardiovascular disease and healthy life expectancy.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.