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1.
Stat Med ; 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38885949

RESUMO

Emergency medical diseases (EMDs) are the leading cause of death worldwide. A time-to-death analysis is needed to accurately identify the risks and describe the pattern of an EMD because the mortality rate can peak early and then decline. Dose-ranging Phase II clinical trials are essential for developing new therapies for EMDs. However, most dose-finding trials do not analyze mortality as a time-to-event endpoint. We propose three Bayesian dose-response time-to-event models for a secondary mortality analysis of a clinical trial: a two-group (active treatment vs control) model, a three-parameter sigmoid EMAX model, and a hierarchical EMAX model. The study also incorporates one specific active treatment as an active comparator in constructing three new models. We evaluated the performance of these six models and a very popular independent model using simulated data motivated by a randomized Phase II clinical trial focused on identifying the most effective hyperbaric oxygen dose to achieve favorable functional outcomes in patients with severe traumatic brain injury. The results show that the three-group, EMAX, and EMAX model with an active comparator produce the smallest averaged mean squared errors and smallest mean absolute biases. We provide a new approach for time-to-event analysis in early-phase dose-ranging clinical trials for EMDs. The EMAX model with an active comparator can provide valuable insights into the mortality analysis of new EMDs or other conditions that have changing risks over time. The restricted mean survival time, a function of the model's hazards, is recommended for displaying treatment effects for EMD research.

2.
Stat Med ; 42(25): 4582-4601, 2023 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-37599009

RESUMO

The Glasgow outcome scale-extended (GOS-E), an ordinal scale measure, is often selected as the endpoint for clinical trials of traumatic brain injury (TBI). Traditionally, GOS-E is analyzed as a fixed dichotomy with favorable outcome defined as GOS-E ≥ 5 and unfavorable outcome as GOS-E < 5. More recent studies have defined favorable vs unfavorable outcome utilizing a sliding dichotomy of the GOS-E that defines a favorable outcome as better than a subject's predicted prognosis at baseline. Both dichotomous approaches result in loss of statistical and clinical information. To improve on power, Yeatts et al proposed a sliding scoring of the GOS-E as the distance from the cutoff for favorable/unfavorable outcomes, and therefore used more information found in the original GOS-E to estimate the probability of favorable outcome. We used data from a published TBI trial to explore the ramifications to trial operating characteristics by analyzing the sliding scoring of the GOS-E as either dichotomous, continuous, or ordinal. We illustrated a connection between the ordinal data and time-to-event (TTE) data to allow use of Bayesian software that utilizes TTE-based modeling. The simulation results showed that the continuous method with continuity correction offers higher power and lower mean squared error for estimating the probability of favorable outcome compared to the dichotomous method, and similar power but higher precision compared to the ordinal method. Therefore, we recommended that future severe TBI clinical trials consider analyzing the sliding scoring of the GOS-E endpoint as continuous with continuity correction.


Assuntos
Lesões Encefálicas Traumáticas , Humanos , Teorema de Bayes , Lesões Encefálicas Traumáticas/terapia , Escala de Resultado de Glasgow , Probabilidade , Prognóstico , Ensaios Clínicos como Assunto
3.
Clin Trials ; 19(6): 636-646, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35786002

RESUMO

BACKGROUND/AIMS: Fibrinolytic therapy with tenecteplase has been proposed for patients with pulmonary embolism but the optimal dose is unknown. Higher-than-necessary dosing is likely to cause excess bleeding. We designed an adaptive clinical trial to identify the minimum and assumed safest dose of tenecteplase that maintains efficacy. METHODS: We propose a Bayesian adaptive, placebo-controlled, group-sequential dose-finding trial using response-adaptive randomization to preferentially allocate subjects to the most promising doses, dual analyses strategies (continuous and dichotomized) using a gatekeeping approach to maximize clinical impact, and interim stopping rules to efficiently address competing trial objectives. The operating characteristics of the proposed design were evaluated using Monte Carlo simulation across multiple hypothetical efficacy scenarios. RESULTS: Simulation demonstrated response-adaptive randomization can preferentially allocate subjects to doses which appear to be performing well based on interim data. Interim decision-making, including the interim evaluation of both analysis strategies with gatekeeping, allows the trial to continue enrollment when success with the dichotomized analysis strategy appears sufficiently likely and to stop enrollment and declare superiority based on the continuous analysis strategy when there is little chance of ultimately declaring superiority with the dichotomized analysis. CONCLUSION: The proposed design allows evaluation of a greater number of dose levels than would be possible with a non-adaptive design and avoids the need to choose either the continuous or the dichotomized analysis strategy for the primary endpoint.


Assuntos
Embolia Pulmonar , Projetos de Pesquisa , Humanos , Doença Aguda , Teorema de Bayes , Ensaios Clínicos como Assunto , Relação Dose-Resposta a Droga , Embolia Pulmonar/tratamento farmacológico , Tenecteplase/uso terapêutico
4.
Circulation ; 140(8): 658-664, 2019 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-31238700

RESUMO

BACKGROUND: In patients with acute minor ischemic stroke or high-risk transient ischemic attack enrolled in the POINT trial (Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke [POINT] Trial), the combination of clopidogrel and aspirin for 90 days reduced major ischemic events but increased major hemorrhage in comparison to aspirin alone. METHODS: In a secondary analysis of POINT (N=4881), we assessed the time course for benefit and risk from the combination of clopidogrel and aspirin. The primary efficacy outcome was a composite of ischemic stroke, myocardial infarction, or ischemic vascular death. The primary safety outcome was major hemorrhage. Risks and benefits were estimated for delayed times of treatment initiation using left-truncated models. RESULTS: Through 90 days, the rate of major ischemic events was initially high then decreased markedly, whereas the rate of major hemorrhage remained low but relatively constant throughout. With the use of a model-based approach, the optimal change point for major ischemic events was 21 days (0-21 days hazard ratio 0.65 for clopidogrel-aspirin versus aspirin; 95% CI, 0.50-0.85; P=0.0015, in comparison to 22-90 days hazard ratio, 1.38; 95% CI, 0.81-2.35; P=0.24). Models showed benefits of clopidogrel-aspirin for treatment delayed as long as 3 days after symptom onset. CONCLUSIONS: The benefit of clopidogrel-aspirin occurs predominantly within the first 21 days, and outweighs the low, but ongoing risk of major hemorrhage. When considered with the results of the CHANCE trial (Clopidogrel in High-Risk Patients With Non-disabling Cerebrovascular Events), a similar trial treating with clopidogrel-aspirin for 21 days and showing no increase in major hemorrhage, these results suggest that limiting clopidogrel-aspirin use to 21 days may maximize benefit and reduce risk after high-risk transient ischemic attack or minor ischemic stroke. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00991029.


Assuntos
Aspirina/uso terapêutico , Clopidogrel/uso terapêutico , Quimioterapia Combinada/efeitos adversos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/prevenção & controle , Hemorragia/prevenção & controle , Isquemia/tratamento farmacológico , Ataque Isquêmico Transitório/tratamento farmacológico , Inibidores da Agregação Plaquetária/uso terapêutico , Acidente Vascular Cerebral/tratamento farmacológico , Fatores de Tempo , Doença Aguda , Aspirina/efeitos adversos , Protocolos Clínicos , Clopidogrel/efeitos adversos , Hemorragia/etiologia , Humanos , Inibidores da Agregação Plaquetária/efeitos adversos , Modelos de Riscos Proporcionais , Risco , Medição de Risco
5.
Stroke ; 50(7): e187-e210, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31104615

RESUMO

In 2005, the American Stroke Association published recommendations for the establishment of stroke systems of care and in 2013 expanded on them with a statement on interactions within stroke systems of care. The aim of this policy statement is to provide a comprehensive review of the scientific evidence evaluating stroke systems of care to date and to update the American Stroke Association recommendations on the basis of improvements in stroke systems of care. Over the past decade, stroke systems of care have seen vast improvements in endovascular therapy, neurocritical care, and stroke center certification, in addition to the advent of innovations, such as telestroke and mobile stroke units, in the context of significant changes in the organization of healthcare policy in the United States. This statement provides an update to prior publications to help guide policymakers and public healthcare agencies in continually updating their stroke systems of care in light of these changes. This statement and its recommendations span primordial and primary prevention, acute stroke recognition and activation of emergency medical services, triage to appropriate facilities, designation of and treatment at stroke centers, secondary prevention at hospital discharge, and rehabilitation and recovery.


Assuntos
Certificação , Serviços Médicos de Emergência , Política Organizacional , Acidente Vascular Cerebral , Serviços Médicos de Emergência/métodos , Serviços Médicos de Emergência/organização & administração , Serviços Médicos de Emergência/normas , Humanos , Guias de Prática Clínica como Assunto , Sociedades Médicas , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/fisiopatologia , Acidente Vascular Cerebral/terapia , Estados Unidos
6.
N Engl J Med ; 375(11): 1033-43, 2016 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-27276234

RESUMO

BACKGROUND: Limited data are available to guide the choice of a target for the systolic blood-pressure level when treating acute hypertensive response in patients with intracerebral hemorrhage. METHODS: We randomly assigned eligible participants with intracerebral hemorrhage (volume, <60 cm(3)) and a Glasgow Coma Scale (GCS) score of 5 or more (on a scale from 3 to 15, with lower scores indicating worse condition) to a systolic blood-pressure target of 110 to 139 mm Hg (intensive treatment) or a target of 140 to 179 mm Hg (standard treatment) in order to test the superiority of intensive reduction of systolic blood pressure to standard reduction; intravenous nicardipine to lower blood pressure was administered within 4.5 hours after symptom onset. The primary outcome was death or disability (modified Rankin scale score of 4 to 6, on a scale ranging from 0 [no symptoms] to 6 [death]) at 3 months after randomization, as ascertained by an investigator who was unaware of the treatment assignments. RESULTS: Among 1000 participants with a mean (±SD) systolic blood pressure of 200.6±27.0 mm Hg at baseline, 500 were assigned to intensive treatment and 500 to standard treatment. The mean age of the patients was 61.9 years, and 56.2% were Asian. Enrollment was stopped because of futility after a prespecified interim analysis. The primary outcome of death or disability was observed in 38.7% of the participants (186 of 481) in the intensive-treatment group and in 37.7% (181 of 480) in the standard-treatment group (relative risk, 1.04; 95% confidence interval, 0.85 to 1.27; analysis was adjusted for age, initial GCS score, and presence or absence of intraventricular hemorrhage). Serious adverse events occurring within 72 hours after randomization that were considered by the site investigator to be related to treatment were reported in 1.6% of the patients in the intensive-treatment group and in 1.2% of those in the standard-treatment group. The rate of renal adverse events within 7 days after randomization was significantly higher in the intensive-treatment group than in the standard-treatment group (9.0% vs. 4.0%, P=0.002). CONCLUSIONS: The treatment of participants with intracerebral hemorrhage to achieve a target systolic blood pressure of 110 to 139 mm Hg did not result in a lower rate of death or disability than standard reduction to a target of 140 to 179 mm Hg. (Funded by the National Institute of Neurological Disorders and Stroke and the National Cerebral and Cardiovascular Center; ATACH-2 ClinicalTrials.gov number, NCT01176565 .).


Assuntos
Anti-Hipertensivos/administração & dosagem , Hemorragia Cerebral/complicações , Hipertensão/tratamento farmacológico , Nicardipino/administração & dosagem , Idoso , Anti-Hipertensivos/efeitos adversos , Hemorragia Cerebral/mortalidade , Hemorragia Cerebral/fisiopatologia , Feminino , Escala de Coma de Glasgow , Humanos , Hipertensão/etiologia , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Nicardipino/efeitos adversos , Falha de Tratamento , Resultado do Tratamento
7.
Stat Med ; 38(17): 3123-3138, 2019 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-31070807

RESUMO

A primary goal of a phase II dose-ranging trial is to identify a correct dose before moving forward to a phase III confirmatory trial. A correct dose is one that is actually better than control. A popular model in phase II is an independent model that puts no structure on the dose-response relationship. Unfortunately, the independent model does not efficiently use information from related doses. One very successful alternate model improves power using a pre-specified dose-response structure. Past research indicates that EMAX models are broadly successful and therefore attractive for designing dose-response trials. However, there may be instances of slight risk of nonmonotone trends that need to be addressed when planning a clinical trial design. We propose to add hierarchical parameters to the EMAX model. The added layer allows information about the treatment effect in one dose to be "borrowed" when estimating the treatment effect in another dose. This is referred to as the hierarchical EMAX model. Our paper compares three different models (independent, EMAX, and hierarchical EMAX) and two different design strategies. The first design considered is Bayesian with a fixed trial design, and it has a fixed schedule for randomization. The second design is Bayesian but adaptive, and it uses response adaptive randomization. In this article, a randomized trial of patients with severe traumatic brain injury is provided as a motivating example.


Assuntos
Ensaios Clínicos Fase II como Assunto , Relação Dose-Resposta a Droga , Oxigenoterapia Hiperbárica , Modelos Estatísticos , Ensaios Clínicos Controlados Aleatórios como Assunto , Projetos de Pesquisa , Teorema de Bayes , Humanos , Estudos Multicêntricos como Assunto , Estudos Prospectivos
8.
Stroke ; 49(6): 1412-1418, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29789395

RESUMO

BACKGROUND AND PURPOSE: We compared the rates of death or disability, defined by modified Rankin Scale score of 4 to 6, at 3 months in patients with intracerebral hemorrhage according to post-treatment systolic blood pressure (SBP)-attained status. METHODS: We divided 1000 subjects with SBP ≥180 mm Hg who were randomized within 4.5 hours of symptom onset as follows: SBP <140 mm Hg achieved or not achieved within 2 hours; subjects in whom SBP <140 mm Hg was achieved within 2 hours were further divided: SBP <140 mm Hg for 21 to 22 hours (reduced and maintained) or SBP was ≥140 mm Hg for at least 2 hours during the period between 2 and 24 hours (reduced but not maintained). RESULTS: Compared with subjects without reduction of SBP <140 mm Hg within 2 hours, subjects with reduction and maintenance of SBP <140 mm Hg within 2 hours had a similar rate of death or disability (relative risk of 0.98; 95% confidence interval, 0.74-1.29). The rates of neurological deterioration within 24 hours were significantly higher in reduced and maintained group (10.4%; relative risk, 1.98; 95% confidence interval, 1.08-3.62) and in reduced but not maintained group (11.5%; relative risk, 2.08; 95% confidence interval, 1.15-3.75) compared with reference group. The rates of cardiac-related adverse events within 7 days were higher among subjects with reduction and maintenance of SBP <140 mmHg compared to subjects without reduction (11.2% versus 6.4%). CONCLUSIONS: No decline in death or disability but higher rates of neurological deterioration and cardiac-related adverse events were observed among intracerebral hemorrhage subjects with reduction with and without maintenance of intensive SBP goals. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01176565.


Assuntos
Anti-Hipertensivos/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Nicardipino/uso terapêutico , Idoso , Determinação da Pressão Arterial/métodos , Hemorragia Cerebral/tratamento farmacológico , Ensaios Clínicos como Assunto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
9.
N Engl J Med ; 371(26): 2457-66, 2014 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-25493974

RESUMO

BACKGROUND: Traumatic brain injury (TBI) is a major cause of death and disability worldwide. Progesterone has been shown to improve neurologic outcome in multiple experimental models and two early-phase trials involving patients with TBI. METHODS: We conducted a double-blind, multicenter clinical trial in which patients with severe, moderate-to-severe, or moderate acute TBI (Glasgow Coma Scale score of 4 to 12, on a scale from 3 to 15, with lower scores indicating a lower level of consciousness) were randomly assigned to intravenous progesterone or placebo, with the study treatment initiated within 4 hours after injury and administered for a total of 96 hours. Efficacy was defined as an increase of 10 percentage points in the proportion of patients with a favorable outcome, as determined with the use of the stratified dichotomy of the Extended Glasgow Outcome Scale score at 6 months after injury. Secondary outcomes included mortality and the Disability Rating Scale score. RESULTS: A total of 882 of the planned sample of 1140 patients underwent randomization before the trial was stopped for futility with respect to the primary outcome. The study groups were similar with regard to baseline characteristics; the median age of the patients was 35 years, 73.7% were men, 15.2% were black, and the mean Injury Severity Score was 24.4 (on a scale from 0 to 75, with higher scores indicating greater severity). The most frequent mechanism of injury was a motor vehicle accident. There was no significant difference between the progesterone group and the placebo group in the proportion of patients with a favorable outcome (relative benefit of progesterone, 0.95; 95% confidence interval [CI], 0.85 to 1.06; P=0.35). Phlebitis or thrombophlebitis was more frequent in the progesterone group than in the placebo group (relative risk, 3.03; CI, 1.96 to 4.66). There were no significant differences in the other prespecified safety outcomes. CONCLUSIONS: This clinical trial did not show a benefit of progesterone over placebo in the improvement of outcomes in patients with acute TBI. (Funded by the National Institute of Neurological Disorders and Stroke and others; PROTECT III ClinicalTrials.gov number, NCT00822900.).


Assuntos
Lesões Encefálicas/tratamento farmacológico , Progesterona/administração & dosagem , Acidentes de Trânsito , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Método Duplo-Cego , Esquema de Medicação , Feminino , Escala de Resultado de Glasgow , Humanos , Infusões Intravenosas , Escala de Gravidade do Ferimento , Masculino , Pessoa de Meia-Idade , Flebite/induzido quimicamente , Progesterona/efeitos adversos , Falha de Tratamento , Adulto Jovem
10.
Clin Trials ; 14(3): 246-254, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28135827

RESUMO

BACKGROUND: Adaptive clinical trials use accumulating data from enrolled subjects to alter trial conduct in pre-specified ways based on quantitative decision rules. In this research, we sought to characterize the perspectives of key stakeholders during the development process of confirmatory-phase adaptive clinical trials within an emergency clinical trials network and to build a model to guide future development of adaptive clinical trials. METHODS: We used an ethnographic, qualitative approach to evaluate key stakeholders' views about the adaptive clinical trial development process. Stakeholders participated in a series of multidisciplinary meetings during the development of five adaptive clinical trials and completed a Strengths-Weaknesses-Opportunities-Threats questionnaire. In the analysis, we elucidated overarching themes across the stakeholders' responses to develop a conceptual model. RESULTS: Four major overarching themes emerged during the analysis of stakeholders' responses to questioning: the perceived statistical complexity of adaptive clinical trials and the roles of collaboration, communication, and time during the development process. Frequent and open communication and collaboration were viewed by stakeholders as critical during the development process, as were the careful management of time and logistical issues related to the complexity of planning adaptive clinical trials. CONCLUSION: The Adaptive Design Development Model illustrates how statistical complexity, time, communication, and collaboration are moderating factors in the adaptive design development process. The intensity and iterative nature of this process underscores the need for funding mechanisms for the development of novel trial proposals in academic settings.


Assuntos
Ensaios Clínicos Adaptados como Assunto/métodos , Pesquisa Biomédica/métodos , Projetos de Pesquisa , Comunicação , Comportamento Cooperativo , Humanos , Modelos Estatísticos , Pesquisa Qualitativa , Inquéritos e Questionários
11.
Pharm Stat ; 15(5): 396-404, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27306921

RESUMO

The goals of phase II clinical trials are to gain important information about the performance of novel treatments and decide whether to conduct a larger phase III trial. This can be complicated in cases when the phase II trial objective is to identify a novel treatment having several factors. Such multifactor treatment scenarios can be explored using fixed sample size trials. However, the alternative design could be response adaptive randomization with interim analyses and additionally, longitudinal modeling whereby more data could be used in the estimation process. This combined approach allows a quicker and more responsive adaptation to early estimates of later endpoints. Such alternative clinical trial designs are potentially more powerful, faster, and smaller than fixed randomized designs. Such designs are particularly challenging, however, because phase II trials tend to be smaller than subsequent confirmatory phase III trials. The phase II trial may need to explore a large number of treatment variations to ensure that the efficacy of optimal clinical conditions is not overlooked. Adaptive trial designs need to be carefully evaluated to understand how they will perform and to take full advantage of their potential benefits. This manuscript discusses a Bayesian response adaptive randomization design with a longitudinal model that uses a multifactor approach for predicting phase III study success via the phase II data. The approach is based on an actual clinical trial design for the hyperbaric oxygen brain injury treatment trial. Specific details of the thought process and the models informing the trial design are provided. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Lesões Encefálicas/terapia , Ensaios Clínicos Fase II como Assunto/estatística & dados numéricos , Oxigenoterapia Hiperbárica/estatística & dados numéricos , Modelos Estatísticos , Causalidade , Ensaios Clínicos Fase II como Assunto/métodos , Humanos , Estudos Longitudinais , Distribuição Aleatória
12.
BMC Med Ethics ; 16: 27, 2015 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-25933921

RESUMO

BACKGROUND: In an adaptive clinical trial (ACT), key trial characteristics may be altered during the course of the trial according to predefined rules in response to information that accumulates within the trial itself. In addition to having distinguishing scientific features, adaptive trials also may involve ethical considerations that differ from more traditional randomized trials. Better understanding of clinical trial experts' views about the ethical aspects of adaptive designs could assist those planning ACTs. Our aim was to elucidate the opinions of clinical trial experts regarding their beliefs about ethical aspects of ACTs. METHODS: We used a convergent, mixed-methods design employing a 22-item ACTs beliefs survey with visual analog scales and open-ended questions and mini-focus groups. We developed a coding scheme to conduct thematic searches of textual data, depicted responses to visual analog scales on box-plot diagrams, and integrated findings thematically. Fifty-three clinical trial experts from four constituent groups participated: academic biostatisticians (n = 5); consultant biostatisticians (n = 6); academic clinicians (n = 22); and other stakeholders including patient advocacy, National Institutes of Health, and U.S. Food and Drug Administration representatives (n = 20). RESULTS: The respondents recognized potential ethical benefits of ACTs, including a higher probability of receiving an effective intervention for participants, optimizing resource utilization, and accelerating treatment discovery. Ethical challenges voiced include developing procedures so trial participants can make informed decisions about taking part in ACTs and plausible, though unlikely risks of research personnel altering enrollment patterns. CONCLUSIONS: Clinical trial experts recognize ethical advantages but also pose potential ethical challenges of ACTs. The four constituencies differ in their weighing of ACT ethical considerations based on their professional vantage points. These data suggest further discussion about the ethics of ACTs is needed to facilitate ACT planning, design and conduct, and ultimately better allow planners to weigh ethical implications of competing trial designs.


Assuntos
Atitude , Pesquisa Biomédica/ética , Consentimento Livre e Esclarecido , Projetos de Pesquisa , Pesquisadores , Pesquisa Biomédica/métodos , Ensaios Clínicos como Assunto , Ética em Pesquisa , Grupos Focais , Humanos , Resultado do Tratamento , Estados Unidos
13.
Ann Emerg Med ; 64(3): 235-244.e5, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24613595

RESUMO

Acute stroke is an important focus of quality improvement efforts. There are many organizations involved in quality measurement for acute stroke, and a complex landscape of quality measures exists. Our objective is to describe and evaluate existing US quality measures for the emergency care of acute ischemic stroke patients in the emergency department (ED) setting. We performed a systematic review of the literature to identify the existing quality measures for the emergency care of acute ischemic stroke. We then convened a panel of experts to appraise how well the measures satisfy the American College of Cardiology/American Heart Association (ACC/AHA) criteria for performance measure development (strength of the underlying evidence, clinical importance, magnitude of the relationship between performance and outcome, and cost-effectiveness). We identified 7 quality measures relevant to the emergency care of acute ischemic stroke that fall into 4 main categories: brain imaging, thrombolytic administration, dysphagia screening, and mortality. Three of the 7 measures met all 4 of the ACC/AHA evaluation criteria: brain imaging within 24 hours, thrombolytic therapy within 3 hours of symptom onset, and thrombolytic therapy within 60 minutes of hospital arrival. Measures not satisfying all evaluation criteria were brain imaging report within 45 minutes, consideration for thrombolytic therapy, dysphagia screening, and mortality rate. There remains room for improvement in the development and use of measures that reflect high-quality emergency care of acute ischemic stroke patients in the United States.


Assuntos
Isquemia Encefálica/terapia , Serviços Médicos de Emergência/normas , Indicadores de Qualidade em Assistência à Saúde/normas , Isquemia Encefálica/diagnóstico , Análise Custo-Benefício , Serviços Médicos de Emergência/economia , Humanos , Qualidade da Assistência à Saúde/normas
14.
Telemed J E Health ; 20(9): 769-800, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24968105

RESUMO

The telemedicine intervention in chronic disease management promises to involve patients in their own care, provides continuous monitoring by their healthcare providers, identifies early symptoms, and responds promptly to exacerbations in their illnesses. This review set out to establish the evidence from the available literature on the impact of telemedicine for the management of three chronic diseases: congestive heart failure, stroke, and chronic obstructive pulmonary disease. By design, the review focuses on a limited set of representative chronic diseases because of their current and increasing importance relative to their prevalence, associated morbidity, mortality, and cost. Furthermore, these three diseases are amenable to timely interventions and secondary prevention through telemonitoring. The preponderance of evidence from studies using rigorous research methods points to beneficial results from telemonitoring in its various manifestations, albeit with a few exceptions. Generally, the benefits include reductions in use of service: hospital admissions/re-admissions, length of hospital stay, and emergency department visits typically declined. It is important that there often were reductions in mortality. Few studies reported neutral or mixed findings.


Assuntos
Doença Crônica/terapia , Gerenciamento Clínico , Telemedicina , Humanos
15.
Ann Emerg Med ; 60(4): 451-7, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22424650

RESUMO

Randomized clinical trials, which aim to determine the efficacy and safety of drugs and medical devices, are a complex enterprise with myriad challenges, stakeholders, and traditions. Although the primary goal is scientific discovery, clinical trials must also fulfill regulatory, clinical, and ethical requirements. Innovations in clinical trials methodology have the potential to improve the quality of knowledge gained from trials, the protection of human subjects, and the efficiency of clinical research. Adaptive clinical trial methods represent a broad category of innovations intended to address a variety of long-standing challenges faced by investigators, such as sensitivity to previous assumptions and delayed identification of ineffective treatments. The implementation of adaptive clinical trial methods, however, requires greater planning and simulation compared with a more traditional design, along with more advanced administrative infrastructure for trial execution. The value of adaptive clinical trial methods in exploratory phase (phase 2) clinical research is generally well accepted, but the potential value and challenges of applying adaptive clinical trial methods in large confirmatory phase clinical trials are relatively unexplored, particularly in the academic setting. In the Adaptive Designs Accelerating Promising Trials Into Treatments (ADAPT-IT) project, a multidisciplinary team is studying how adaptive clinical trial methods could be implemented in planning actual confirmatory phase trials in an established, National Institutes of Health-funded clinical trials network. The overarching objectives of ADAPT-IT are to identify and quantitatively characterize the adaptive clinical trial methods of greatest potential value in confirmatory phase clinical trials and to elicit and understand the enthusiasms and concerns of key stakeholders that influence their willingness to try these innovative strategies.


Assuntos
Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Ensaios Clínicos Fase II como Assunto/métodos , Interpretação Estatística de Dados , Término Precoce de Ensaios Clínicos/métodos , Humanos , Comunicação Interdisciplinar , Projetos de Pesquisa , Tamanho da Amostra
16.
JAMA Netw Open ; 5(5): e2211616, 2022 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-35544137

RESUMO

Importance: Bayesian adaptive trial design has the potential to create more efficient clinical trials. However, a barrier to the uptake of bayesian adaptive designs for confirmatory trials is limited experience with how they may perform compared with a frequentist design. Objective: To compare the performance of a bayesian and a frequentist adaptive clinical trial design. Design, Setting, and Participants: This prospective cohort study compared 2 trial designs for a completed multicenter acute stroke trial conducted within a National Institutes of Health neurologic emergencies clinical trials network, with individual patient-level data, including the timing and order of enrollments and outcome ascertainment, from 1151 patients with acute stroke and hyperglycemia randomized to receive intensive or standard insulin therapy. The implemented frequentist design had group sequential boundaries for efficacy and futility interim analyses at 90 days after randomization for 500, 700, 900, and 1100 patients. The bayesian alternative used predictive probability of trial success to govern early termination for efficacy and futility with a first interim analysis at 500 randomized patients and subsequent interims after every 100 randomizations. Main Outcomes and Measures: The main outcome was the sample size at end of study, which was defined as the sample size at which each of the studies stopped accrual of patients. Results: Data were collected from 1151 patients. As conducted, the frequentist design passed the futility boundary after 936 participants were randomized. Using the same sequence and timing of randomization and outcome data, the bayesian alternative crossed the futility boundary approximately 3 months earlier after 800 participants were randomized. Conclusions and Relevance: Both trial designs stopped for futility before reaching the planned maximum sample size. In both cases, the clinical community and patients would benefit from learning the answer to the trial's primary question earlier. The common feature across the 2 designs was frequent interim analyses to stop early for efficacy or for futility. Differences between how these analyses were implemented between the 2 trials resulted in the differences in early stopping.


Assuntos
Hiperglicemia , Acidente Vascular Cerebral , Teorema de Bayes , Humanos , Hiperglicemia/tratamento farmacológico , Insulina/uso terapêutico , Insulina Regular Humana , Estudos Prospectivos , Acidente Vascular Cerebral/tratamento farmacológico , Estados Unidos
17.
Stroke ; 42(6): 1621-5, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21546491

RESUMO

BACKGROUND AND PURPOSE: The Albumin in Acute Stroke (ALIAS) Part 2 Trial is directly testing whether 2 g/kg of 25% human albumin (ALB) administered intravenously within 5 hours of ischemic stroke onset results in improved clinical outcome. Recruitment into Part 1 of the ALIAS Trial was halted for safety reasons. ALIAS Part 2 is a new, reformulated trial with more-stringent exclusion criteria. Our aim was to explore the efficacy of ALB in the ALIAS Part 1 data and to assess the statistical assumptions underlying the ALIAS Part 2 Trial. METHODS: ALIAS is a multicenter, blinded, randomized controlled trial. Data on 434 subjects, comprising the ALIAS Part 1 subjects, were analyzed. We examined both the thrombolysis and nonthrombolysis cohorts combined and separately in a "target population" by excluding subjects who would not have been eligible for the ALIAS Part 2 Trial; the latter comprised patients >83 years of age, those with elevated baseline troponin values, and those with in-hospital stroke. We examined the differences in the primary composite outcome, defined as a modified Rankin Scale score of 0 to 1 and/or a National Institutes of Health Stroke Scale score of 0 to 1 at 90 days after randomization. RESULTS: In the combined thrombolysis plus nonthrombolysis cohorts of the target population, 44.7% of subjects in the ALB group had a favorable outcome compared with 36.0% in the saline group (absolute effect size=8.7%; 95% CI, -2.2% to 19.5%). Among thrombolyzed subjects of the target population, 46.7% had a favorable outcome in the ALB group compared with 36.6% in the saline group (absolute effect size=10.1%; 95% CI, -2.0% to 20.0%). CONCLUSIONS: Preliminary results from the ALIAS Part 1 suggest a trend toward a favorable primary outcome in subjects treated with ALB and support the validity of the statistical assumptions that underlie the ALIAS Part 2 Trial. The ALIAS Part 2 Trial will confirm or refute these results. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov/ALIAS. Unique identifier: NCT00235495.


Assuntos
Albuminas/uso terapêutico , Acidente Vascular Cerebral/tratamento farmacológico , Resultado do Tratamento , Idoso , Idoso de 80 Anos ou mais , Método Duplo-Cego , Humanos , Masculino , Terapia Trombolítica/métodos
18.
J Emerg Med ; 40(1): 82-92, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20576390

RESUMO

BACKGROUND: Ischemic cerebrovascular accidents remain a leading cause of morbidity and mortality. Thrombolytic therapy for acute ischemic stroke within 3h of symptom onset of highly select patients has been advocated by some groups since 1995, but trials have yielded inconsistent outcomes. One recent trial demonstrated significant improvement when the therapeutic window was extended to 4.5h. CLINICAL QUESTION: Does the intravenous systemic administration of tPA within 4.5h to select patients with acute ischemic stroke improve functional outcomes? EVIDENCE REVIEW: All randomized controlled trials enrolling patients within 4.5h were identified, in addition to a meta-analysis of these trial data. RESULTS: The National Institute of Neurological Disorders and Stroke (NINDS) and European Cooperative Acute Stroke Study III (ECASS III) clinical trials demonstrated significantly improved outcomes at 3 months, with increased rates of intracranial hemorrhage, whereas ECASS II and the Acute Noninterventional Therapy in Ischemic Stroke (ATLANTIS) study showed increased hemorrhagic complications without improving outcomes. Meta-analysis of trial data from all ECASS trials, NINDS, and ATLANTIS suggest that thrombolysis within 4.5h improves functional outcomes. CONCLUSION: Ischemic stroke tPA treatment within 4.5h seems to improve functional outcomes and increases symptomatic intracranial hemorrhage rates without significantly increasing mortality.


Assuntos
Isquemia Encefálica/complicações , Acidente Vascular Cerebral/tratamento farmacológico , Terapia Trombolítica , Doença Aguda , Adolescente , Adulto , Idoso , Medicina Baseada em Evidências , Feminino , Humanos , Pessoa de Meia-Idade , Ensaios Clínicos Controlados Aleatórios como Assunto , Acidente Vascular Cerebral/etiologia , Fatores de Tempo , Ativador de Plasminogênio Tecidual/administração & dosagem , Resultado do Tratamento
19.
Res Pract Thromb Haemost ; 5(5): e12563, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34278192

RESUMO

OBJECTIVE: Alterations in coagulation could mediate functional outcome in patients with hyperglycemia after acute ischemic stroke (AIS). We prospectively studied the effects of intensive versus standard glucose control on coagulation markers and their relationships to functional outcomes in patients with AIS. APPROACH: The Insights on Selected Procoagulation Markers and Outcomes in Stroke Trial measured the coagulation biomarkers whole blood tissue factor procoagulant activity (TFPCA); plasma factors VII (FVII), VIIa (FVIIa), and VIII (FVIII); thrombin-antithrombin (TAT) complex; D-dimer; tissue factor pathway inhibitor, and plasminogen activator inhibitor-1 (PAI-1) antigen in patients enrolled in the Stroke Hyperglycemia Insulin Network Effort trial of intensive versus standard glucose control on functional outcome at 3 months after AIS. Changes in biomarkers over time (from baseline ≈12 hours after stroke onset) to 48 hours, and changes in biomarkers between treatment groups, functional outcomes, and their interaction were analyzed by two-way analysis of variance. RESULTS: A total of 125 patients were included (57 in the intensive treatment group and 68 in the standard treatment group). The overall mean age was 66 years; 42% were women. Changes from baseline to 48 hours in coagulation markers were significantly different between treatment groups for TFPCA (P = 0.02) and PAI-1 (P = .04) and FVIIa (P = .04). Increases in FVIIa and decreases in FVIII were associated with favorable functional outcomes (P = .04 and .04, respectively). In the intensive treatment group, reductions in TFPCA and FVIII and increases in FVIIa were greater in patients with favorable than unfavorable outcomes (P = .02, 0.002, 0.03, respectively). In the standard treatment group, changes in FVII were different by functional outcome (P = .006). CONCLUSIONS: Intensive glucose control induced greater alterations in coagulation biomarkers than standard treatment, and these were associated with a favorable functional outcome at 3 months after AIS.

20.
Ann Emerg Med ; 56(5): 538-50, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21036294

RESUMO

STUDY OBJECTIVE: The National Institutes of Health (NIH) formed an NIH Task Force on Research in Emergency Medicine to enhance NIH support for emergency care research. The NIH Trauma Research Roundtable was convened on June 22 to 23, 2009. The objectives of the roundtable are to identify key research questions essential to advancing the scientific underpinnings of emergency trauma care and to discuss the barriers and best means to advance research by exploring the role of trauma research networks and collaboration between NIH and the emergency trauma care community. METHODS: Before the roundtable, the emergency care domains to be discussed were selected and experts in each of the fields were invited to participate in the roundtable. Domain experts were asked to identify research priorities and challenges and separate them into mechanistic, translational, and clinical categories. During and after the conference, the lists were circulated among the participants and revised to reach a consensus. RESULTS: Emergency trauma care research is characterized by focus on the timing, sequence, and time sensitivity of disease processes and treatment effects. Rapidly identifying the phenotype of patients on the time spectrum of acuity and severity after injury and the mechanistic reasons for heterogeneity in outcome are important challenges in emergency trauma research. Other research priorities include the need to elucidate the timing, sequence, and duration of causal molecular and cellular events involved in time-critical injuries, and the development of treatments capable of halting or reversing them; the need for novel experimental models of acute injury; the need to assess the effect of development and aging on the postinjury response; and the need to understand why there are regional differences in outcomes after injury. Important barriers to emergency care research include a limited number of trained investigators and experienced mentors, limited research infrastructure and support, and regulatory hurdles. CONCLUSION: The science of emergency trauma care may be advanced by facilitating the following: (1) development of an acute injury template for clinical research; (2) developing emergency trauma clinical research networks; (3) integrating emergency trauma research into Clinical and Translational Science Awards; (4) developing emergency care-specific initiatives within the existing structure of NIH institutes and centers; (5) involving acute trauma and emergency specialists in grant review and research advisory processes; (6) supporting learn-phase or small, clinical trials; (7) performing research to address ethical and regulatory issues; and (8) training emergency care investigators with research training programs.


Assuntos
Pesquisa Biomédica , Serviços Médicos de Emergência , National Institutes of Health (U.S.) , Ferimentos e Lesões/terapia , Comitês Consultivos , Sistema Nervoso Central/lesões , Ensaios Clínicos como Assunto , Medicina de Emergência/educação , Humanos , Avaliação das Necessidades , Choque Hemorrágico/etiologia , Choque Hemorrágico/terapia , Pesquisa Translacional Biomédica , Estados Unidos , Recursos Humanos
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