Bruce Ovbiagele

University of Toronto, Toronto, Ontario, Canada

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Publications (340)1758.66 Total impact

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    ABSTRACT: Background Retrospective analyses of randomized controlled trials suggest that antiplatelet therapy may modify the potential cerebrovascular benefits of lowering homocysteine with B-vitamins among individuals with cardiovascular disease. We evaluated the effects of B-vitamin supplementation on risk of subsequent stroke among high cardiovascular risk individuals who are not taking antiplatelet medications.
    Preview · Article · Feb 2016 · International Journal of Stroke
  • Ali Razmara · Bruce Ovbiagele · Daniela Markovic · Amytis Towfighi
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    ABSTRACT: Background: Expert consensus guidelines recommend antihypertensive treatment to lower secondary stroke risk, but patterns and predictors of blood pressure (BP) treatment and control among stroke survivors in the United States remain unknown. Understanding predictors of poor control can facilitate development of targeted strategies. Methods: We reviewed the prevalence and control of hypertension among adults 40 years or older with self-reported stroke who participated in the National Health and Nutrition Examination Surveys 1999-2004 with mortality follow-up through 2006. Predictors of poorly controlled BP (>140/90 mm Hg) and nontreatment were determined via logistic regression. Independent association between antihypertensive use and mortality was determined using Cox models. Results: Among 9145 participants, 490 reported previous stroke; 72% had known hypertension, 8% had undiagnosed hypertension, and 47% had poorly controlled BP. In multivariable analyses, age (odds ratio [OR] per year 1.06, 95% confidence interval [CI] 1.03-1.09), female sex (OR 1.70, 95% CI 1.12-2.57), non-Mexican Hispanic ethnicity (OR 4.54, 95% CI 1.76-11.70), black race (OR 3.15, 95% CI 1.59-6.25), hypercholesterolemia (OR 2.46, 95% CI 1.44-4.21), and diabetes (OR 1.96, 95% CI 1.16-3.33) were associated with poorly controlled BP. Obesity was associated with lower odds of poorly controlled BP (OR .51, 95% CI .26-.99). Non-Mexican Hispanic ethnicity (OR 7.37, 95% CI 2.25-24.10) and black race (OR 3.13, 95% CI 1.05-9.34) were predictors of nontreatment, whereas diabetes was linked to treatment (OR 3.57, 95% CI 1.21-10.43). There was no association between antihypertensive treatment and mortality after adjustment for demographics and comorbidities. Conclusions: One in 2 stroke survivors in the United States has poorly controlled BP; the most vulnerable groups include women, non-Mexican Hispanics, blacks, diabetics, and older individuals. Understanding causes of this evidence-practice gap may assist in developing effective targeted interventions.
    No preview · Article · Jan 2016 · Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association
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    Meng Lee · Yi-Ling Wu · Bruce Ovbiagele
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    ABSTRACT: Background and purpose: The burden of stroke is comparatively greater in Asian countries than in the Western world. While there has been a documented recent decline in the incidence of stroke in several Western nations due to better risk factor management, much less is known about the nature and trajectory of stroke in Asia over the last decade. The objective of this study was to explore risk factors, medication use, incidence, and one-year recurrence of stroke in Taiwan. Methods: We conducted a nationwide cohort study by reviewing all hospitalized patients (≥ 18 years) with a primary diagnosis of ischemic stroke between 2001 and 2011 from Taiwan National Health Insurance Research Database. Results: A total of 291,381 first-ever ischemic stroke patients were enrolled between 2000 and 2011. The average age was about 70 years and approximately 58.6% of them were men. While prevalence of diabetes mellitus and hyperlipidemia, as well as use of statins, antiplatelet agents, and oral anticoagulant agents for atrial fibrillation significantly increased; incidence (142.3 vs. 129.5 per 100,000 in 2000 and 2011, respectively) and one-year recurrence (9.6% vs. 7.8% in 2000 and 2011, respectively) of stroke declined during this period of time. Conclusions: Over the last decade in Taiwan, rates of primary ischemic stroke and one-year recurrent stroke decreased by 9% and 18% respectively.
    Preview · Article · Dec 2015
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    ABSTRACT: Background: The American Heart Association developed criteria dubbed "Life's Simple 7" defining ideal cardiovascular health: not smoking, regular physical activity, healthy diet, maintaining normal weight, and controlling cholesterol, blood pressure, and blood glucose levels. The impact of achieving these metrics on survival after stroke is unknown. We aimed to determine cardiovascular health scores among stroke survivors in the United States and to assess the link between cardiovascular health score and all-cause mortality after stroke. Methods and results: We assessed cardiovascular health metrics among a nationally representative sample of US adults with stroke (n=420) who participated in the National Health and Nutrition Examination Surveys in 1988-1994 (with mortality assessment through 2006). We determined cumulative all-cause mortality by cardiovascular health score under the Cox proportional hazards model after adjusting for sociodemographic characteristics and comorbidities. No stroke survivors met all 7 ideal health metrics. Over a median duration of 98 months (range, 53-159), there was an inverse dose-dependent relationship between number of ideal lifestyle metrics met and 10-year adjusted mortality: 0 to 1: 57%; 2: 48%; 3: 43%; 4: 36%; and ≥5: 30%. Those who met ≥4 health metrics had lower all-cause mortality than those who met 0 to 1 (hazard ratio, 0.51; 95% confidence interval, 0.28-0.92). After adjusting for sociodemographics, higher health score was associated with lower all-cause mortality (trend P-value, 0.022). Conclusions: Achieving a greater number of ideal cardiovascular health metrics is associated with lower long-term risk of dying after stroke. Specifically targeting "Life's Simple 7" goals might have a profound impact, extending survival after stroke.
    No preview · Article · Nov 2015 · Journal of the American Heart Association
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    ABSTRACT: Background and purpose: The Questionnaire for Verifying Stroke-Free Status (QVSFS), a method for verifying stroke-free status in participants of clinical, epidemiological, and genetic studies, has not been validated in low-income settings where populations have limited knowledge of stroke symptoms. We aimed to validate QVSFS in 3 languages, Yoruba, Hausa and Akan, for ascertainment of stroke-free status of control subjects enrolled in an on-going stroke epidemiological study in West Africa. Methods: Data were collected using a cross-sectional study design where 384 participants were consecutively recruited from neurology and general medicine clinics of 5 tertiary referral hospitals in Nigeria and Ghana. Ascertainment of stroke status was by neurologists using structured neurological examination, review of case records, and neuroimaging (gold standard). Relative performance of QVSFS without and with pictures of stroke symptoms (pictograms) was assessed using sensitivity, specificity, positive predictive value, and negative predictive value. Results: The overall median age of the study participants was 54 years and 48.4% were males. Of 165 stroke cases identified by gold standard, 98% were determined to have had stroke, whereas of 219 without stroke 87% were determined to be stroke-free by QVSFS. Negative predictive value of the QVSFS across the 3 languages was 0.97 (range, 0.93-1.00), sensitivity, specificity, and positive predictive value were 0.98, 0.82, and 0.80, respectively. Agreement between the questionnaire with and without the pictogram was excellent/strong with Cohen k=0.92. Conclusions: QVSFS is a valid tool for verifying stroke-free status across culturally diverse populations in West Africa.
    Full-text · Article · Nov 2015 · Stroke
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    ABSTRACT: Background The Global Alliance for Chronic Diseases comprises the majority of the world’s public research funding agencies. It is focussed on implementation research to tackle the burden of chronic diseases in low- and middle-income countries and amongst vulnerable populations in high-income countries. In its inaugural research call, 15 projects were funded, focussing on lowering blood pressure-related disease burden. In this study, we describe a reflexive mapping exercise to identify the behaviour change strategies undertaken in each of these projects. Methods Using the Behaviour Change Wheel framework, each team rated the capability, opportunity and motivation of the various actors who were integral to each project (e.g. community members, non-physician health workers and doctors in projects focussed on service delivery). Teams then mapped the interventions they were implementing and determined the principal policy categories in which those interventions were operating. Guidance was provided on the use of Behaviour Change Wheel to support consistency in responses across teams. Ratings were iteratively discussed and refined at several group meetings. Results There was marked variation in the perceived capabilities, opportunities and motivation of the various actors who were being targeted for behaviour change strategies. Despite this variation, there was a high degree of synergy in interventions functions with most teams utilising complex interventions involving education, training, enablement, environmental restructuring and persuasion oriented strategies. Similar policy categories were also targeted across teams particularly in the areas of guidelines, communication/marketing and service provision with few teams focussing on fiscal measures, regulation and legislation. Conclusions The large variation in preparedness to change behaviour amongst the principal actors across these projects suggests that the interventions themselves will be variably taken up, despite the similarity in approaches taken. The findings highlight the importance of contextual factors in driving success and failure of research programmes. Forthcoming outcome and process evaluations from each project will build on this exploratory work and provide a greater understanding of factors that might influence scale-up of intervention strategies. Electronic supplementary material The online version of this article (doi:10.1186/s13012-015-0331-0) contains supplementary material, which is available to authorized users.
    Full-text · Article · Nov 2015 · Implementation Science
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    Oh Young Bang · Bruce Ovbiagele · Jong S. Kim

    Full-text · Article · Oct 2015 · Stroke
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    ABSTRACT: As a scientific field of study, neuroepidemiology encompasses more than just the descriptive study of the frequency, distribution, determinants and outcomes of neurologic diseases in populations. It also includes experimental aspects that span the full spectrum of clinical and population science research. As such, neuroepidemiology has a strong potential to inform implementation research for global stroke prevention and treatment. This review begins with an overview of the progress that has been made in descriptive and experimental neuroepidemiology over the past quarter century with emphasis on standards for evidence generation, critical appraisal of that evidence and impact on clinical and public health practice at the national, regional and global levels. Specific advances made in high-income countries as well as in low- and middle-income countries are presented. Gaps in implementation as well as evidence gaps in stroke research, stroke burden, clinical outcomes and disparities between developed and developing countries are then described. The continuing need for high quality neuroepidemiologic data in low- and middle-income countries is highlighted. Additionally, persisting disparities in stroke burden and care by sex, race, ethnicity, income and socioeconomic status are discussed. The crucial role that national stroke registries have played in neuroepidemiologic research is also addressed. Opportunities presented by new directions in comparative effectiveness and implementation research are discussed as avenues for turning neuroepidemiological insights into action to maximize health impact and to guide further biomedical research on neurological diseases.
    Full-text · Article · Oct 2015 · Neuroepidemiology

  • No preview · Article · Oct 2015 · Journal of the neurological sciences
  • J.‐H. Park · B. Ovbiagele

    No preview · Article · Oct 2015 · European Journal of Neurology
  • Rong Chen · Chun Li · Bruce Ovbiagele · Daniel Lackland · Wayne Feng

    No preview · Conference Paper · Oct 2015
  • Bruce Ovbiagele

    No preview · Article · Sep 2015
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    ABSTRACT: The economic and social costs of stroke to the society can be enormous. These costs can cause serious economic damage to both the individual and the nation. It is thus important to conduct a cost effectiveness analysis to indicate whether an intervention provides high value where its health benefits justify its costs. This study will provide evidence based on the costs of stroke with a view of improving intervention and treatments of stoke survivors in Nigeria. This study utilizes two types of economic evaluation methods - cost-effectiveness analysis and cost-benefit analysis - to determine the economic impact of Tailored Hospital-based Risk Reduction to Impede Vascular Events after Stroke (THRIVES) intervention. The study is conducted in four Nigerian hospitals where 400 patients are recruited to participate in the study. The cost-effectiveness of THRIVES post-discharge intervention is compared with the control Intervention scenario, which is the usual and customary care delivered at each health facility in terms of cost per quality adjusted life years (QALYs). It is expected that successful implementation of the project would serve as a model of cost-effective quality stroke care for implementation. Award Number: U01 NS079179. Trial registration: RL: http://www.clinicaltrials.gov. Unique identifier: NCT01900756
    Full-text · Article · Sep 2015
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    ABSTRACT: Endovascular treatment is increasingly being used in acute stroke care. However, although stent retrievers show improved flow restoration rates, their clinical benefits have been uncertain. To assess the incremental effect of using stent retrievers compared with intravenous tissue plasminogen activator (IV tPA; alteplase) alone or placebo/control. We conducted a pooled analysis of 4 studies using stent retrievers (Solitaire), IV tPA, or placebo/control. We applied the ischemic stroke risk score (www.sorcan.ca/iscore) to each participant to adjust for differences in baseline characteristics. We used a shift analysis to account for the potential benefits across the entire modified Rankin scale score at 90 days, adjusting for time-to-treatment, baseline Alberta Stroke Program Early CT score, and ischemic stroke risk score. Of the 915 participants in this analysis, 312 (34.1%) patients received placebo, 312 (34.1%) received tPA alone, 131 (14.4%) received stent retrievers alone, and 160 (17.5) received combined therapy (IV tPA plus stent retrievers). The shift analysis revealed that more patients remained independent at 90 days if receiving stent retrievers alone (number needed to treat 3.5) or combined with tPA (number needed to treat 3.1) compared with tPA alone. After adjustment, participants receiving stent retrievers alone (odds ratio, 2.95; 95% confidence interval, 1.48-5.89) or combined with tPA (odds ratio, 4.45; 95% confidence interval, 2.40-8.27) were more likely to be independent at 90 days compared with tPA alone. Patients with acute ischemic stroke who received IV tPA or revascularization therapies had a higher likelihood of achieving independence at 3 months. Stent retriever technology combined with tPA was associated with the greatest benefit compared with placebo, tPA alone, or endovascular therapy alone. ASPECTS, the Alberta Stroke Program Early CT scoreESCAPE, The Endovascular Treatment for Small Core and Proximal Occlusion Ischemic StrokeiScore, ischemic stroke risk scoreIV, intravenousMR CLEAN, Multicenter Randomized Clinical trial of Endovascular treatment for Acute ischemic stroke in the NetherlandsmRS, modified Rankin scaleNIHSS, National Institutes of Health Stroke ScaleNINDS, National Institute of Neurological Diseases and StrokesICH, symptomatic intracerebral hemorrhageSTAR, the Solitaire Flow Restoration Thrombectomy for Acute RevascularizationSWIFT, Solitaire flow restoration device vs the Merci Retriever in patients with acute ischemic stroketPA, tissue plasminogen activator (alteplase)WHO, World Health Organization.
    No preview · Article · Sep 2015 · Neurosurgery
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    ABSTRACT: As the second leading cause of death and the leading cause of adult-onset disability, stroke is a major public health concern particularly pertinent in Sub-Saharan Africa (SSA), where nearly 80% of all global stroke mortalities occur, and stroke burden is projected to increase in the coming decades. However, traditional and emerging risk factors for stroke in SSA have not been well characterized, thus limiting efforts at curbing its devastating toll. The Stroke Investigative Research and Education Network (SIREN) project is aimed at comprehensively evaluating the key environmental and genomic risk factors for stroke (and its subtypes) in SSA while simultaneously building capacities in phenomics, biobanking, genomics, biostatistics, and bioinformatics for brain research. SIREN is a transnational, multicentre, hospital and community-based study involving 3,000 cases and 3,000 controls recruited from 8 sites in Ghana and Nigeria. Cases will be hospital-based patients with first stroke within 10 days of onset in whom neurovascular imaging will be performed. Etiological and topographical stroke subtypes will be documented for all cases. Controls will be hospital- and community-based participants, matched to cases on the basis of gender, ethnicity, and age (±5 years). Information will be collected on known and proposed emerging risk factors for stroke. Study Significance: SIREN is the largest study of stroke in Africa to date. It is anticipated that it will shed light on the phenotypic characteristics and risk factors of stroke and ultimately provide evidence base for strategic interventions to curtail the burgeoning burden of stroke on the sub-continent. © 2015 S. Karger AG, Basel.
    Full-text · Article · Aug 2015 · Neuroepidemiology
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    ABSTRACT: Accumulating data based on model-derived estimates suggest rising rates of stroke in sub-Saharan Africa over the next several decades. Stroke is a leading cause of death, disability, and dementia worldwide. Directly enumerated hospital-based data on the longitudinal trajectory of stroke admissions and deaths in sub-Saharan Africa could help hospital administrators, public health officials, and government policy-makers with planning and utilization of scarce resources. To evaluate 30-year trends in stroke admission and mortality rates in central Ghana. We undertook a retrospective analysis of data on stroke admissions and mortality at a tertiary referral hospital in central Ghana between 1983 and 2013. Rates of stroke admissions and mortality were expressed as stroke admissions or deaths divided by total number of hospital admissions or deaths respectively. Yearly crude case fatality from stroke was calculated and predictors of stroke mortality were determined using Cox proportional hazards regression analysis. Over the period, there were 12,233 stroke admissions with equal gender distribution. The rate of stroke admissions increased progressively from 5.32/1000 admissions in 1983 to 13.85/1000 admissions in 2010 corresponding to a 260% rise over the period. Stroke mortality rates also increased from 3.40/1000 deaths to 6.66/1000 deaths over the 30-year period. The average 28-day mortality over the period was 41.1%. Predictors of in-patient mortality were increasing age-aHR of 1.31 (1.16-1.47) for age>80years compared with <40years and admissions in 2000's compared with 1980's; aHR of 1.32 (1.26-1.39). Of the 1132 stroke patients with neuroimaging data: 569 (50.3%) had intracerebral hemorrhage, 382 (33.7%) had ischemic stroke and 181 (16.0) had sub-arachnoid hemorrhage. Patients with ischemic stroke were significantly older than those with ICH and SAH respectively. Rates of stroke admission and mortality have increased steadily over the past three decades in central Ghana. More intensive risk modification and optimization of acute stroke care are urgently needed to stem these worrisome trends. Copyright © 2015. Published by Elsevier B.V.
    No preview · Article · Aug 2015 · Journal of the neurological sciences
  • Julia M Rothlisberger · Bruce Ovbiagele
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    ABSTRACT: Stroke exacts a huge toll physically, mentally and economically. Antiplatelet therapy is the cornerstone of secondary stroke prevention, and proven drugs available to successfully realize this therapeutic strategy for the long term include aspirin, dipyridamole plus aspirin and clopidogrel. However, government agencies, corporations, health plans and patients desire more information about the clinical- and cost-effectiveness of these established therapies in real-world settings. This paper provides an update on evidence-based secondary stroke prevention with antiplatelet medications, discusses cost-related issues and offers perspective about the future.
    No preview · Article · Aug 2015 · Journal of Comparative Effectiveness Research

  • No preview · Article · Jul 2015 · Stroke
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    ABSTRACT: The aim of this guideline is to provide a focused update of the current recommendations for the endovascular treatment of acute ischemic stroke. Where there is overlap, the recommendations made here supersede those of previous guidelines. This focused update analyzes results from 8 randomized clinical trials of endovascular treatment and other relevant data published since 2013. It is not intended to be a complete literature review from the date of the previous guideline publication but rather to include pivotal new evidence that justifies changes in current recommendations. Members of the writing committee were appointed by the American Heart Association/American Stroke Association Stroke Council's Scientific Statement Oversight Committee and the American Heart Association/American Stroke Association Manuscript Oversight Committee (MOC). Strict adherence to the American Heart Association conflict of interest policy was maintained throughout the consensus process. Recommendations follow the American Heart Association/American Stroke Association methods of classifying the level of certainty of the treatment effect and the class of evidence. Prerelease review of the draft guideline was performed by 6 expert peer reviewers and by the members of the Stroke Council Scientific Statement Oversight Committee and Stroke Council Leadership Committee. Evidence-based guidelines are presented for the selection of patients with acute ischemic stroke for endovascular treatment, the endovascular procedure and for systems of care to facilitate endovascular treatment. Certain endovascular procedures have been demonstrated to provide clinical benefit in selected patients with acute ischemic stroke. Systems of care should be organized to facilitate the delivery of this care. © 2015 American Heart Association, Inc.
    Preview · Article · Jun 2015 · Stroke
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    ABSTRACT: Lack of insurance is a barrier to optimal stroke risk factor control but data on its long-term impact on stroke outcomes are sparse. We assessed the association between health insurance and long-term mortality after stroke. Using data from the National Health and Nutrition Examination Surveys 1999-2004 with follow-up mortality assessment through 2006, we examined the independent effect of health insurance on (1) stroke mortality among all adult participants (n = 15,049) and (2) vascular and all-cause mortality rates among participants with self-reported stroke (n = 563). Among individuals without a previous stroke, uninsured individuals aged less than 65 years were more likely to die of stroke than those with insurance (adjusted hazard ratio [HR], 3.13; 95% confidence interval [CI], .96-10.23); however, among those aged 65 years or older, those with private insurance, private plus Medicare, or Medicare plus Medicaid had similar risk of stroke mortality when compared to those with Medicare alone. Stroke survivors aged 65 years or older with private insurance were less likely to die from vascular causes (adjusted HR, .38; 95% CI, .23-.63) compared to those with Medicare alone. For stroke survivors aged less than 65 years, uninsured individuals had similar all-cause mortality rates compared to their counterparts with insurance. Insurance status influences risk of dying from a stroke in the general population, as well as long-term mortality rates among stroke survivors in the United States, but these relationships vary by age. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.
    No preview · Article · Jun 2015 · Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association

Publication Stats

7k Citations
1,758.66 Total Impact Points

Institutions

  • 2016
    • University of Toronto
      Toronto, Ontario, Canada
  • 2015
    • University of Ulsan
      • Department of Neurology
      Ulsan, Ulsan, South Korea
    • Rancho Los Amigos Rehabilitation Center
      Downey, California, United States
  • 2012-2015
    • Medical University of South Carolina
      Charleston, South Carolina, United States
  • 2014
    • Myongji Hospital
      Kōyō, Gyeonggi Province, South Korea
  • 2011-2013
    • University of California, San Diego
      • Department of Neurosciences
      San Diego, California, United States
  • 2003-2012
    • University of California, Los Angeles
      • • Department of Neurology
      • • Center for Neurobiology of Stress
      Los Ángeles, California, United States
    • Beth Israel Deaconess Medical Center
      • Department of Neurology
      Boston, MA, United States
  • 2004-2011
    • Harbor-UCLA Medical Center
      • Department of Emergency Medicine
      Torrance, California, United States
  • 2005-2010
    • University of Southern California
      • • Department of Neurology
      • • Keck School of Medicine
      Los Ángeles, California, United States
  • 2003-2010
    • Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center
      • Department of Medicine
      Torrance, California, United States
  • 2008
    • Sungkyunkwan University
      • Samsung Medical Center
      Sŏul, Seoul, South Korea
  • 2007
    • Ajou University
      Sŏul, Seoul, South Korea
  • 2006
    • Bristol-Myers Squibb
      New York, New York, United States