Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 33
Filtrar
2.
BMJ Open ; 9(12): e031895, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31831540

RESUMO

INTRODUCTION: Perioperative benzodiazepines are used because of their anxiolytic, sedative and amnestic effects. Evidence has demonstrated an association of benzodiazepines with adverse neuropsychiatric effects. Nonetheless, because of their potential benefits, perioperative benzodiazepines continue to be used routinely. We seek to evaluate the body of evidence of the risks and benefits of benzodiazepine use during the perioperative period. METHODS AND ANALYSIS: We will search Cochrane CENTRAL, MEDLINE, EMBASE, PsychINFO, CINAHL and Web of Science from inception to March 2019 for randomised controlled trials (RCTs) and observational studies evaluating the administration of benzodiazepine medications as compared with all other medications (or nothing) in patients undergoing cardiac and non-cardiac surgery. We will exclude studies assessing the use of benzodiazepines for procedural sedation or day surgery. We will examine the impact of giving these medications before, during and after surgery. Outcomes of interest include the incidence of delirium, duration of delirium, postprocedure cognitive change, the incidence of intraoperative awareness, patient satisfaction/quality of life/quality of recovery, length-of-stay (LOS) in the intensive care unit (ICU), hospital LOS and in-hospital mortality.Reviewers will screen references and assess eligibility using predefined criteria independently and in duplicate. Two reviewers will independently collect data using prepiloted forms. We will present results separately for RCTs and observational studies. We will pool data using a random effect model and present results as relative risk with 95% CIs for dichotomous outcomes and mean difference with 95% CI for continuous outcomes. We will pool adjusted ORs for observational studies. We will assess risk of bias for individual studies using the Cochrane Collaboration tool for RCTs. For observational studies, we will use tools designed by the Clinical Advances through Research and Information Translation group. Quality of evidence for each outcome will be assessed using the Grading of Recommendations Assessment, Development and Evaluation approach. ETHICS AND DISSEMINATION: This systematic review involves no patient contact and no interaction with healthcare providers or systems. As such, we did not seek ethics board approval. We will disseminate the findings of our systematic review through the presentation at peer-reviewed conferences and by seeking publication in a peer-reviewed journal. PROSPERO REGISTRATION NUMBER: CRD42019128144.

3.
Anesthesiol Clin ; 37(4): 801-813, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31677692

RESUMO

This article provides an overview of knowledge gaps that need to be addressed in cardiac anesthesia, including mitigating the inflammatory effects of cardiopulmonary bypass, defining myocardial infarction after cardiac surgery, improving perioperative neurologic outcomes, and the optimal management of patients undergoing valve replacement. In addition, emerging approaches to research conduct are discussed, including the use of new analytical techniques like machine learning, pragmatic trials, and adaptive designs.

5.
BMJ Open ; 9(9): e028585, 2019 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-31530593

RESUMO

INTRODUCTION: Bleeding during cardiac surgery is associated with increased morbidity and mortality. Tranexamic acid is an antifibrinolytic with proven efficacy in major surgeries. Current clinical practice guidelines recommend intraoperative use in cardiac procedures. However, several complications have been reported with tranexamic acid including seizures. This review intends to summarise the evidence examining the efficacy and safety of tranexamic acid in patients undergoing cardiac surgery. METHODS/DESIGN: We will search MEDLINE, Embase, PubMED, ACPJC, CINAHL and the Cochrane trial registry for eligible randomised controlled trials, the search dates for all databases will be from inception until 1 January 2019, investigating the perioperative use of topical and/or intravenous tranexamic acid as a stand-alone antifibrinolytic agent compared with placebo in patients undergoing open cardiac surgery. We categorised outcomes as patient critical or patient important. Selected patient-critical outcomes are: mortality (intensive care unit, hospital and 30-day endpoints), reoperation within 24 hours, postoperative bleeding requiring transfusion of packed red blood cells, myocardial infarction, stroke, pulmonary embolism, bowel infarction, upper or lower limb deep vein thrombosis and seizures. Those outcomes, we perceived as clinical experts to be most patient valued and patients were not involved in outcomes selection process. We will not apply publication date, language, journal or methodological quality restrictions. Two reviewers will independently screen and identify eligible studies using predefined eligibility criteria and then review full reports of all potentially relevant citations. A third reviewer will resolve disagreements if consensus cannot be achieved. We will present the results as relative risk with 95% CIs for dichotomous outcomes and as mean difference or standardised mean difference for continuous outcomes with 95% CIs. We will assess the quality of evidence using the Grading of Recommendations, Assessment, Development and Evaluation approach. ETHICS AND DISSEMINATION: Formal ethical approval is not required as primary data will not be collected. The results will be disseminated through a peer-reviewed publication TRIAL REGISTRATION NUMBER: CRD42018105904.

6.
CMAJ ; 191(30): E830-E837, 2019 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-31358597

RESUMO

BACKGROUND: Among adults undergoing contemporary noncardiac surgery, little is known about the frequency and timing of death and the associations between perioperative complications and mortality. We aimed to establish the frequency and timing of death and its association with perioperative complications. METHODS: We conducted a prospective cohort study of patients aged 45 years and older who underwent inpatient noncardiac surgery at 28 centres in 14 countries. We monitored patients for complications until 30 days after surgery and determined the relation between these complications and 30-day mortality using a Cox proportional hazards model. RESULTS: We included 40 004 patients. Of those, 715 patients (1.8%) died within 30 days of surgery. Five deaths (0.7%) occurred in the operating room, 500 deaths (69.9%) occurred after surgery during the index admission to hospital and 210 deaths (29.4%) occurred after discharge from the hospital. Eight complications were independently associated with 30-day mortality. The 3 complications with the largest attributable fractions (AF; i.e., potential proportion of deaths attributable to these complications) were major bleeding (6238 patients, 15.6%; adjusted hazard ratio [HR] 2.6, 95% confidence interval [CI] 2.2-3.1; AF 17.0%); myocardial injury after noncardiac surgery [MINS] (5191 patients, 13.0%; adjusted HR 2.2, 95% CI 1.9-2.6; AF 15.9%); and sepsis (1783 patients, 4.5%; adjusted HR 5.6, 95% CI 4.6-6.8; AF 12.0%). INTERPRETATION: Among adults undergoing noncardiac surgery, 99.3% of deaths occurred after the procedure and 44.9% of deaths were associated with 3 complications: major bleeding, MINS and sepsis. Given these findings, focusing on the prevention, early identification and management of these 3 complications holds promise for reducing perioperative mortality. Study registration: ClinicalTrials.gov, no. NCT00512109.

7.
Genes Dev ; 33(5-6): 294-309, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30804225

RESUMO

The mammalian circadian clock relies on the transcription factor CLOCK:BMAL1 to coordinate the rhythmic expression of thousands of genes. Consistent with the various biological functions under clock control, rhythmic gene expression is tissue-specific despite an identical clockwork mechanism in every cell. Here we show that BMAL1 DNA binding is largely tissue-specific, likely because of differences in chromatin accessibility between tissues and cobinding of tissue-specific transcription factors. Our results also indicate that BMAL1 ability to drive tissue-specific rhythmic transcription is associated with not only the activity of BMAL1-bound enhancers but also the activity of neighboring enhancers. Characterization of physical interactions between BMAL1 enhancers and other cis-regulatory regions by RNA polymerase II chromatin interaction analysis by paired-end tag (ChIA-PET) reveals that rhythmic BMAL1 target gene expression correlates with rhythmic chromatin interactions. These data thus support that much of BMAL1 target gene transcription depends on BMAL1 capacity to rhythmically regulate a network of enhancers.


Assuntos
Fatores de Transcrição ARNTL/genética , Fatores de Transcrição ARNTL/metabolismo , Regulação da Expressão Gênica/genética , Motivos de Aminoácidos/genética , Animais , Cromatina/metabolismo , Ritmo Circadiano/genética , Elementos Facilitadores Genéticos/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Especificidade de Órgãos , Regiões Promotoras Genéticas/genética , Ligação Proteica , RNA Polimerase II/metabolismo
8.
Thromb Haemost ; 119(2): 328-339, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30616247

RESUMO

BACKGROUND: The optimal antithrombotic therapy after surgical bioprosthetic aortic valve replacement (BAVR) is uncertain. We conducted a systematic review and meta-analysis of observational studies and randomized controlled trials (RCTs) comparing antiplatelet therapy and anticoagulation in patients with surgical BAVR. METHODS: We searched Cochrane CENTRAL, MEDLINE and EMBASE from inception to 3 November 2017 for studies evaluating antiplatelet therapy versus anticoagulation early after surgical BAVR. We performed title and abstract screening, full-text review, risk of bias evaluation and data collection independently and in duplicate. We evaluated overall quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation framework, and pooled data using a random effects model. RESULTS: We identified 2 RCTs (n = 397) and 5 observational studies (n = 2,012) meeting our eligibility criteria. The mean follow-up for all outcomes was 3 months in RCTs, and 10 months for observational studies. Antiplatelet compared with anticoagulant therapy demonstrated a trend towards fewer major bleeds in RCTs (relative risk [RR], 0.34; 95% confidence interval [CI], 0.11-1.04, p = 0.06, I 2 = 0%, low quality evidence), and significantly fewer major bleeds in observational studies (RR, 0.34; 95% CI, 0.20-0.58, p ≤ 0.0001, I 2 = 0%, very low quality evidence), but stroke, thromboembolism and mortality did not show a significant difference in either RCTs or observational studies. CONCLUSION: Antiplatelet therapy demonstrated reduced bleeding risk with no negative effects on stroke, thromboembolism or mortality compared with anticoagulation therapy after surgical BAVR. Our confidence in the results is reduced by the low quality of the available evidence.


Assuntos
Anticoagulantes/uso terapêutico , Valva Aórtica/cirurgia , Bioprótese , Doenças das Valvas Cardíacas/cirurgia , Inibidores da Agregação de Plaquetas/uso terapêutico , Coagulação Sanguínea , Seguimentos , Próteses Valvulares Cardíacas , Hemorragia/tratamento farmacológico , Humanos , Estudos Observacionais como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto , Risco , Tromboembolia/prevenção & controle
12.
BMJ Open ; 8(7): e021521, 2018 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-29982215

RESUMO

OBJECTIVES: Covert stroke after non-cardiac surgery may have substantial impact on duration and quality of life. In non-surgical patients, covert stroke is more common than overt stroke and is associated with an increased risk of cognitive decline and dementia. Little is known about covert stroke after non-cardiac surgery.NeuroVISION is a multicentre, international, prospective cohort study that will characterise the association between perioperative acute covert stroke and postoperative cognitive function. SETTING AND PARTICIPANTS: We are recruiting study participants from 12 tertiary care hospitals in 10 countries on 5 continents. PARTICIPANTS: We are enrolling patients ≥65 years of age, requiring hospital admission after non-cardiac surgery, who have an anticipated length of hospital stay of at least 2 days after elective non-cardiac surgery that occurs under general or neuraxial anaesthesia. PRIMARY AND SECONDARY OUTCOME MEASURES: Patients are recruited before elective non-cardiac surgery, and their cognitive function is measured using the Montreal Cognitive Assessment (MoCA) instrument. After surgery, a brain MRI study is performed between postoperative days 2 and 9 to determine the presence of acute brain infarction. One year after surgery, the MoCA is used to assess postoperative cognitive function. Physicians and patients are blinded to the MRI study results until after the last patient follow-up visit to reduce outcome ascertainment bias.We will undertake a multivariable logistic regression analysis in which the dependent variable is the change in cognitive function 1 year after surgery, and the independent variables are acute perioperative covert stroke as well as other clinical variables that are associated with cognitive dysfunction. CONCLUSIONS: The NeuroVISION study will characterise the epidemiology of covert stroke and its clinical consequences. This will be the largest and the most comprehensive study of perioperative stroke after non-cardiac surgery. TRIAL REGISTRATION NUMBER: NCT01980511; Pre-results.


Assuntos
Disfunção Cognitiva/fisiopatologia , Tempo de Internação/estatística & dados numéricos , Complicações Pós-Operatórias/fisiopatologia , Acidente Vascular Cerebral/fisiopatologia , Procedimentos Cirúrgicos Operatórios/efeitos adversos , Idoso , Cognição , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/etiologia , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Período Perioperatório , Complicações Pós-Operatórias/diagnóstico por imagem , Estudos Prospectivos , Acidente Vascular Cerebral/diagnóstico por imagem
13.
Sci Rep ; 8(1): 6759, 2018 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-29712995

RESUMO

Thirty-day readmission after surgery has been proposed as a quality-of-care indicator. We explored the effect of postoperative rehabilitation on readmission risk after groin hernia repair. We used the French National Discharge Database to identify all index hospitalizations for groin hernia repair in 2011. Readmissions within 30 days of discharge were clinically classified in terms of their relationship to the index stay. We used logistic regression to adjust the risk of readmission for patient, procedure and hospital factors. Among 122,952 index hospitalizations for inguinal hernia repair, 3,357 (2.7%) related 30-day readmissions were recorded. Reiterated analyses indicated that readmission risk was consistently associated with patient complexity: age (per year after 60 years, OR 1.03, 95% CI 1.02-1.03, P < 0.001), hospitalization within the previous year (OR 1.56, 95% CI 1.44-1.69, P < 0.001), and increasing severity and combination of co-morbidities. Postoperative rehabilitation was identified as a protective factor (OR 0.56, 95% CI 0.46-0.69, P < 0.001). Older patients and those with greater comorbidity are at elevated risk of readmission after inguinal hernia repair. Postoperative rehabilitation may reduce this risk. Further studies are warranted to confirm the protective effect of postoperative rehabilitation.


Assuntos
Virilha/cirurgia , Hérnia Inguinal/reabilitação , Herniorrafia/reabilitação , Complicações Pós-Operatórias/reabilitação , Idoso , Feminino , Virilha/fisiopatologia , Hérnia Inguinal/epidemiologia , Hérnia Inguinal/fisiopatologia , Hérnia Inguinal/cirurgia , Herniorrafia/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Alta do Paciente , Readmissão do Paciente , Complicações Pós-Operatórias/fisiopatologia , Procedimentos Cirúrgicos Reconstrutivos/efeitos adversos , Procedimentos Cirúrgicos Reconstrutivos/reabilitação , Fatores de Risco
14.
Thromb Haemost ; 118(5): 906-913, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29614524

RESUMO

BACKGROUND: Guidelines recommend higher international normalized ratio (INR) targets for patients with mechanical valves believed to be at higher risk for thromboembolism. Higher INR targets are associated with increased bleeding risk. We performed a systematic review and meta-analysis assessing effects of lower and higher INR targets on thromboembolic and bleeding risk in patients with mechanical heart valves. METHODS: We searched Cochrane CENTRAL, MEDLINE and EMBASE for randomized controlled trials (RCTs) evaluating lower versus higher INR targets for adults with bileaflet mechanical valves. We performed title and abstract screening, full-text review, risk of bias evaluation and data collection independently and in duplicate. We pooled data using a random effects model and used the Grading of Recommendations Assessment, Development and Evaluation framework to evaluate overall quality of evidence. RESULTS: We identified six RCTs (n = 5,497). Lower INR targets were associated with significantly less bleeding-22% versus 40% (relative risk [RR]: 0.54, 95% confidence interval [CI]: 0.31, 0.93, p = 0.03, very low quality). There was no difference in thromboembolism-2% in both groups (RR: 1.28, 95% CI: 0.88, 1.85, p = 0.20, very low quality) or mortality-5.5% with lower INR targets versus 8.5% (RR: 1.00, 95% CI: 0.82, 1.21, p = 0.47, moderate quality). CONCLUSION: In patients with mechanical valves, higher INR targets are not supported by current evidence, which is of very low quality. In fact, our systematic review suggests that lower INR targets offer significantly lower bleeding risks with no significant difference in thromboembolic risk.


Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Monitoramento de Medicamentos/métodos , Fibrinolíticos/uso terapêutico , Implante de Prótese de Valva Cardíaca/efeitos adversos , Valvas Cardíacas/cirurgia , Coeficiente Internacional Normatizado , Tromboembolia/prevenção & controle , Medicina Baseada em Evidências , Fibrinolíticos/efeitos adversos , Próteses Valvulares Cardíacas , Implante de Prótese de Valva Cardíaca/instrumentação , Hemorragia/induzido quimicamente , Humanos , Valor Preditivo dos Testes , Ensaios Clínicos Controlados Aleatórios como Assunto , Medição de Risco , Fatores de Risco , Tromboembolia/sangue , Tromboembolia/diagnóstico , Tromboembolia/etiologia , Resultado do Tratamento
15.
Can J Anaesth ; 65(7): 813-821, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29671186

RESUMO

Increasingly, clinicians and researchers recognize that studies of interventions need to evaluate not only their therapeutic efficacy (i.e., the effect on an outcome in ideal, controlled settings) but also their real-world effectiveness in broad, unselected patient groups. Effectiveness trials inform clinical practice by comparing variations in therapeutic approaches that fall within the standard of care. In this article, we discuss the need for studies of comparative effectiveness in anesthesia and the limitations of individual patient randomized-controlled trials in determining comparative effectiveness. We introduce the concept of randomized cluster crossover trials as a means of answering questions of comparative effectiveness in anesthesia, using the design of the Benzodiazepine-Free Cardiac Anesthesia for Reduction in Postoperative Delirium (B-Free) trial (Clinicaltrials.gov identifier NCT03053869).


Assuntos
Anestesia em Procedimentos Cardíacos/métodos , Delírio/prevenção & controle , Complicações Pós-Operatórias/prevenção & controle , Ensaios Clínicos Controlados Aleatórios como Assunto , Benzodiazepinas/farmacologia , Estudos Cross-Over , Coleta de Dados , Interpretação Estatística de Dados , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto/economia , Ensaios Clínicos Controlados Aleatórios como Assunto/ética , Tamanho da Amostra
16.
Healthc Manage Forum ; 31(2): 57-61, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29488408

RESUMO

Engaging patients and families in research and the design of quality improvement is an essential component of Patient and Family Centred Care (PFCC). Alberta Health Services (AHS) has been engaging patients and families to promote a cultural shift towards PFCC. The AHS trains patient and family advisors to share their experiences and encourages staff to work with advisors to co-design improvements in care. This article briefly describes the role and growth of patient and family advisors, advisory groups, and the participation of advisors in research initiatives through AHS' Strategic Clinical NetworksTM. It also describes recent efforts to build AHS' patient and family engagement capacity by introducing standard patient engagement training, supporting the creation of the innovative Patient and Community Engagement Research internship program, and by developing tools to measure the impact of patient and advisors on AHS. And finally, this article provides key learnings for health leaders.


Assuntos
Participação do Paciente , Melhoria de Qualidade/organização & administração , Qualidade da Assistência à Saúde/normas , Alberta , Segurança do Paciente/normas , Assistência Centrada no Paciente/normas , Pesquisa
17.
Europace ; 20(9): 1442-1450, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-29186407

RESUMO

Aims: The aim of this review was to assess the effect of concomitant surgical atrial fibrillation (AF) ablation on postoperative freedom from AF and patient-important outcomes. Methods and results: We searched Cochrane CENTRAL, MEDLINE, and EMBASE databases from inception to May 2016 for randomized controlled trials (RCTs) evaluating surgical AF ablation using any lesion set vs. no surgical AF ablation in adults with AF undergoing cardiac surgery. We performed screening, risk-of-bias evaluation, and data collection independently and in duplicate. We evaluated risk of bias with the modified Cochrane tool, quality of evidence using GRADE framework, and pooled data with a random-effects model. Of the 23 included studies, only one was considered at low risk of bias. Surgical AF ablation was associated with more freedom from AF at 12 months [relative risk (RR) = 2.32, 95% confidence interval (CI) 1.92-2.80; P < 0.001, low quality]. However, no significant difference was seen in mortality (RR = 1.07, 95% CI 0.72-1.52; P = 0.41, moderate quality), stroke (RR = 1.19, 95% CI 0.59-2.39; P = 0.63, moderate quality), or pacemaker implantation (RR = 1.28, 95% CI 0.85-1.95; P = 0.24, high quality). Comparing biatrial and left-sided lesion sets showed no difference in mortality (P-interaction = 0.60) or stroke (P-interaction = 0.12). At 12 months, biatrial procedures led to more freedom from AF (RR = 2.80, 95% CI 2.13-3.68; P < 0.0001) when compared with left-sided ablation (RR = 2.00, 95% CI 1.68-2.39; P < 0.0001) (P-interaction = 0.04) Biatrial procedures appear to increase the risk for pacemaker (RR = 2.68, 95% CI 1.41-5.11; P = 0.002) compared with no ablation while left-sided ablation does not (RR = 1.08, 95% CI 0.67-1.74; P = 0.76) (P-interaction = 0.03). Conclusion: Surgical AF ablation during cardiac surgery improves freedom from AF. However, impact on patient-important outcomes including mortality and stroke has not shown statistical significance in current RCT evidence. Biatrial compared with left-sided lesion sets showed no difference in mortality or stroke but were associated with significantly increased freedom from AF and risk for pacemaker requirement.


Assuntos
Fibrilação Atrial/cirurgia , Procedimentos Cirúrgicos Cardíacos/métodos , Ablação por Cateter/métodos , Criocirurgia/métodos , Micro-Ondas/uso terapêutico , Fibrilação Atrial/complicações , Humanos , Mortalidade , Marca-Passo Artificial , Implantação de Prótese/estatística & dados numéricos , Ablação por Radiofrequência/métodos , Ensaios Clínicos Controlados Aleatórios como Assunto , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/prevenção & controle , Resultado do Tratamento
18.
Can J Anaesth ; 65(3): 263-271, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29256063

RESUMO

BACKGROUND: Benzodiazepines are commonly administered during cardiac surgery because of their limited effect on hemodynamics and presumed role in preventing intraoperative awareness. Recent concerns about an increased risk of delirium with benzodiazepines have resulted in decreased usage in the intensive care unit and in geriatric perioperative practice. Little is known, however, about current benzodiazepine usage in the setting of adult cardiac surgery. METHODS: We contacted all academic anesthesia departments in Canada to identify practicing attending cardiac anesthesiologists; this group constituted our sampling frame. Information regarding participant demographics, benzodiazepine usage, type, dose, and other administration details were obtained by electronic survey. Responses were analyzed descriptively. RESULTS: The survey was completed by 243/346 (70%) of cardiac anesthesiologists. Eleven percent of respondents do not administer benzodiazepines. Midazolam was the most commonly used benzodiazepine, with a mean (standard deviation) dose of 4.9 (3.8) mg given to an average patient. When respondents were asked the proportion of patients that they gave benzodiazepines, the response was bimodal. The most common considerations that influenced benzodiazepine use were patient age (73%), patient anxiety (63%), history of alcohol/drug/benzodiazepine use (60%), and the presence of risk factors for intraoperative awareness (44%). CONCLUSIONS: Benzodiazepine use is common among academic cardiac anesthesiologists in Canada. Nonetheless, heterogeneity exists between individual practices, suggesting clinical equipoise between restrictive and liberal administration of benzodiazepines for cardiac anesthesia. L'administration de benzodiazépines pendant la chirurgie cardiaque chez l'adulte: évaluation de la pratique actuelle des anesthésiologistes canadiens exerçant en milieu universitaire.


Assuntos
Anestesiologistas/estatística & dados numéricos , Benzodiazepinas/administração & dosagem , Procedimentos Cirúrgicos Cardíacos/métodos , Midazolam/administração & dosagem , Padrões de Prática Médica/estatística & dados numéricos , Centros Médicos Acadêmicos , Canadá , Pesquisas sobre Serviços de Saúde , Humanos
19.
Pharmacoepidemiol Drug Saf ; 26(12): 1513-1519, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28984050

RESUMO

OBJECTIVE: As covariates are not always adequately balanced after propensity score matching and double- adjustment can be used to remove residual confounding, we compared the performance of several double-robust estimators in different scenarios. METHODS: We conducted a series of Monte Carlo simulations on virtual observational studies. After estimating the propensity scores by logistic regression, we performed 1:1 optimal, nearest-neighbor, and caliper matching. We used 4 estimators on each matched sample: (1) a crude estimator without double-adjustment, (2) double-adjustment for the propensity scores, (3) double-adjustment for the unweighted unbalanced covariates, and (4) double-adjustment for the unbalanced covariates, weighted by their strength of association with the outcome. RESULTS: The crude estimator led to highest bias in all tested scenarios. Double-adjustment for the propensity scores effectively removed confounding only when the propensity score models were correctly specified. Double-adjustment for the unbalanced covariates was more robust to misspecification. Double-adjustment for the weighted unbalanced covariates outperformed the other approaches in every scenario and using any matching algorithm, as measured by the mean squared error. CONCLUSION: Double-adjustment can be used to remove residual confounding after propensity score matching. The unbalanced covariates with the strongest confounding effects should be adjusted.


Assuntos
Pontuação de Propensão , Viés , Simulação por Computador , Interpretação Estatística de Dados , Humanos , Modelos Logísticos , Modelos Estatísticos , Método de Monte Carlo , Período Perioperatório , Projetos de Pesquisa/normas
20.
CMAJ Open ; 5(3): E594-E603, 2017 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-28943515

RESUMO

INTRODUCTION: Various definitions of bleeding have been used in perioperative studies without systematic assessment of the diagnostic criteria for their independent association with outcomes important to patients. Our proposed definition of bleeding impacting mortality after noncardiac surgery (BIMS) is bleeding that is independently associated with death during or within 30 days after noncardiac surgery. We describe our analysis plan to sequentially 1) establish the diagnostic criteria for BIMS, 2) estimate the independent contribution of BIMS to 30-day mortality and 3) develop and internally validate a clinical prediction guide to estimate patient-specific risk of BIMS. METHODS: In the Vascular Events In Noncardiac Surgery Patients Cohort Evaluation (VISION) study, we prospectively collected bleeding data for 16 079 patients aged 45 years or more who had noncardiac inpatient surgery between 2007 and 2011 at 12 centres in 8 countries across 5 continents. We will include bleeding features independently associated with 30-day mortality in the diagnostic criteria for BIMS. Candidate features will include the need for reoperation due to bleeding, the number of units of erythrocytes transfused, the lowest postoperative hemoglobin concentration, and the absolute and relative decrements in hemoglobin concentration from the preoperative value. We will then estimate the incidence of BIMS and its independent association with 30-day mortality. Last, we will construct and internally validate a clinical prediction guide for BIMS. INTERPRETATION: This study will address an important gap in our knowledge about perioperative bleeding, with implications for the 200 million patients who undergo noncardiac surgery globally every year. Trial registration: ClinicalTrials.gov, no NCT00512109.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA