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1.
Anesthesiology ; 134(1): 15-25, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33216849

RESUMO

Interest in developing and using novel biomarkers in critical care and perioperative medicine is increasing. Biomarkers studies are often presented with flaws in the statistical analysis that preclude them from providing a scientifically valid and clinically relevant message for clinicians. To improve scientific rigor, the proper application and reporting of traditional and emerging statistical methods (e.g., machine learning) of biomarker studies is required. This Readers' Toolbox article aims to be a starting point to nonexpert readers and investigators to understand traditional and emerging research methods to assess biomarkers in critical care and perioperative medicine.


Assuntos
Biomarcadores , Cuidados Críticos/estatística & dados numéricos , Medicina Perioperatória/estatística & dados numéricos , Interpretação Estatística de Dados , Humanos , Aprendizado de Máquina , Medição de Risco
3.
Br J Anaesth ; 2020 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-32768179

RESUMO

BACKGROUND: We aimed to establish diagnostic criteria for bleeding independently associated with mortality after noncardiac surgery (BIMS) defined as bleeding during or within 30 days after noncardiac surgery that is independently associated with mortality within 30 days of surgery, and to estimate the proportion of 30-day postoperative mortality potentially attributable to BIMS. METHODS: This was a prospective cohort study of participants ≥45 yr old having inpatient noncardiac surgery at 12 academic hospitals in eight countries between 2007 and 2011. Cox proportional hazards models evaluated the adjusted relationship between candidate diagnostic criteria for BIMS and all-cause mortality within 30 days of surgery. RESULTS: Of 16 079 participants, 2.0% (315) died and 36.1% (5810) met predefined screening criteria for bleeding. Based on independent association with 30-day mortality, BIMS was identified as bleeding leading to a postoperative haemoglobin <70 g L-1, transfusion of ≥1 unit of red blood cells, or that was judged to be the cause of death. Bleeding independently associated with mortality after noncardiac surgery occurred in 17.3% of patients (2782). Death occurred in 5.8% of patients with BIMS (161/2782), 1.3% (39/3028) who met bleeding screening criteria but not BIMS criteria, and 1.1% (115/10 269) without bleeding. BIMS was associated with mortality (adjusted hazard ratio: 1.87; 95% confidence interval: 1.42-2.47). We estimated the proportion of 30-day postoperative deaths potentially attributable to BIMS to be 20.1-31.9%. CONCLUSIONS: Bleeding independently associated with mortality after noncardiac surgery (BIMS), defined as bleeding that leads to a postoperative haemoglobin <70 g L-1, blood transfusion, or that is judged to be the cause of death, is common and may account for a quarter of deaths after noncardiac surgery. CLINICAL TRIAL REGISTRATION: NCT00512109.

4.
Br J Anaesth ; 2020 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-32718723

RESUMO

BACKGROUND: Diagnostic criteria for Bleeding Independently associated with Mortality after noncardiac Surgery (BIMS) have been defined as bleeding that leads to a postoperative haemoglobin <70 g L-1, leads to blood transfusion, or is judged to be the direct cause of death. Preoperative prediction guides for BIMS can facilitate informed consent and planning of perioperative care. METHODS: In a prospective cohort study of 16 079 participants aged ≥45 yr having inpatient noncardiac surgery at 12 academic hospitals in eight countries between 2007 and 2011, 17.3% (2782) experienced BIMS. An electronic risk calculator for BIMS was developed and internally validated by logistic regression with bootstrapping, and further simplified to a risk index. Decision curve analysis assessed the potential utility of each prediction guide compared with a strategy of identifying risk of BIMS based on preoperative haemoglobin <120 g L-1. RESULTS: With information about the type of surgery, preoperative haemoglobin, age, sex, functional status, kidney function, history of high-risk coronary artery disease, and active cancer, the risk calculator accurately predicted BIMS (bias-corrected C-statistic, 0.84; 95% confidence interval, 0.837-0.852). A simplified index based on preoperative haemoglobin <120 g L-1, open surgery, and high-risk surgery also predicted BIMS, but less accurately (C-statistic, 0.787; 95% confidence interval, 0.779-0.796). Both prediction guides could improve decision making compared with knowledge of haemoglobin <120 g L-1 alone. CONCLUSIONS: BIMS, defined as bleeding that leads to a postoperative haemoglobin <70 g L-1, leads to blood transfusion, or that is judged to be the direct cause of death, can be predicted by a simple risk index before surgery. CLINICAL TRIAL REGISTRATION: NCT00512109.

5.
Crit Care ; 24(1): 384, 2020 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-32600392

RESUMO

BACKGROUND: Intensive care unit (ICU) hospitalisations of elderly patients with acute respiratory infection have increased, yet the long-term effects of ICU admission among elderly individuals remain unknown. We examined differences over the 2 years after discharge in mortality, healthcare utilisation and frailty score between elderly survivors of ARI in the ICU and an elderly control population. METHODS: We used 2009-2017 data from 39 hospital discharge databases. Patients ≥ 80 years old discharged alive from ICU hospitalisation for acute respiratory infection were propensity score-matched with controls (cataract surgery) discharged from the hospital at the same time and adjusted for age, sex and comorbidities present before hospitalisation. We reported 2-year mortality and compared healthcare utilisation and frailty scores in the 2-year periods before and after ICU hospitalisation. RESULTS: One thousand two hundred and twenty elderly survivors of acute respiratory infection in the ICU were discharged, and 988 were successfully matched with controls. After discharge, patients had a 10.1-fold [95% CI, 6.1-17.3] higher risk of death at 6 months and 3.6-fold [95% CI, 2.9-4.6] higher risk of death at 2 years compared with controls. They also had a 2-fold increase in both healthcare utilisation and frailty score in the 2 years after hospital discharge, whereas healthcare utilisation and frailty scores among controls were stable before and after hospitalisation. CONCLUSIONS: We observed a substantially increased rate of death in the years following ICU hospitalisation for elderly patients along with elevated healthcare resource use and accelerated age-associated decline as assessed by frailty score. These findings provide data for better informed goals-of-care discussions and may help target post-ICU discharge services.

6.
Pilot Feasibility Stud ; 6: 104, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32699643

RESUMO

Background: Surgical bleeding is associated with postoperative cardiovascular complications. The efficacy and safety of tranexamic acid (TXA) in noncardiac surgery are still uncertain. Statins may prevent perioperative cardiovascular complications. We conducted a pilot to assess the feasibility of a perioperative trial of TXA and rosuvastatin. Methods: Using a factorial design, we randomized patients at cardiovascular risk undergoing noncardiac surgery to intravenous TXA (1 g at the start and end of surgery) or placebo, and oral rosuvastatin (40 mg before and 20 mg daily for 30 days after surgery) or placebo. Feasibility outcomes included recruitment rates, follow-up, and compliance to interventions. Clinical outcomes were secondarily explored. Results: After 3 months, we changed the design to a partial factorial due to the difficult recruitment of statin-naive patients. Over 6 months, 100 patients were randomized in the TXA trial (49 TXA, 51 placebo), 34 in the rosuvastatin trial (18 rosuvastatin, 16 placebo). Ninety-two percent (95% CI 80-98) of TXA and 86% (95% CI 74-94) of TXA-placebo patients received the 2 study doses. Thirty-three percent (95% CI 13-59) of rosuvastatin patients and 37% (95% CI 15-65) of rosuvastatin-placebo patients discontinued the study drug. A major cardiovascular complication occurred at 30 days in 1 TXA and 6 TXA-placebo patients, and 1 rosuvastatin and no rosuvastatin-placebo patients. Conclusions: Our pilot study supports the feasibility of a perioperative TXA trial in noncardiac surgery. Feasibility of a perioperative rosuvastatin trial is uncertain because of a high prevalence of statin use in the target population and concerns about compliance. Trial registration: ClinicalTrials.govNCT02546648.

7.
J Clin Med ; 9(8)2020 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-32722204

RESUMO

Hip fracture (HF) in older patients is associated with a high six-month mortality rate. Several clinical conditions may affect outcome, including baseline characteristics, co-existing acute illnesses, perioperative factors, and postoperative complications. Our primary objective was to estimate the respective effect of these four domains on six-month mortality after HF. A retrospective observational study using a monocentric cohort of older patients was conducted. All patients ≥ 70 years old admitted to the emergency department for HF and hospitalized in our perioperative geriatric care unit from June 2009 to September 2018 were included. Among 1015 included patients, five (0.5%) were lost to follow-up, and 1010 were retained in the final analysis (mean age 86 ± 6 years). The six-month mortality rate was 14.8%. The six-month attributable mortality estimates were as follows: baseline characteristics (including age, gender, comorbidities, autonomy, type of fracture): 62.4%; co-existing acute illnesses (including acute events present before surgery that could result from the fracture or cause it): 0% (not significantly associated with six-month mortality); perioperative factors (including blood transfusion and delayed surgery): 12.3%; severe postoperative complications: 11.9%. Baseline characteristics explained less than two-thirds of the six-month mortality after HF. Optimizing patients care by improving management of perioperative factors and thus decreasing postoperative complications, could reduce by a maximum of one quarter of the six-month mortality rate after HF.

8.
J Clin Epidemiol ; 125: 47-56, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32464321

RESUMO

OBJECTIVE: Causal treatment effects are estimated at the population level in randomized controlled trials, while clinical decision is often to be made at the individual level in practice. We aim to show how clinical prediction models used under a counterfactual framework may help to infer individualized treatment effects. STUDY DESIGN AND SETTING: As an illustrative example, we reanalyze the International Stroke Trial. This large, multicenter trial enrolled 19,435 adult patients with suspected acute ischemic stroke from 36 countries, and reported a modest average benefit of aspirin (vs. no aspirin) on a composite outcome of death or dependency at 6 months. We derive and validate multivariable logistic regression models that predict the patient counterfactual risks of outcome with and without aspirin, conditionally on 23 predictors. RESULTS: The counterfactual prediction models display good performance in terms of calibration and discrimination (validation c-statistics: 0.798 and 0.794). Comparing the counterfactual predicted risks on an absolute difference scale, we show that aspirin-despite an average benefit-may increase the risk of death or dependency at 6 months (compared with the control) in a quarter of stroke patients. CONCLUSIONS: Counterfactual prediction models could help researchers and clinicians (i) infer individualized treatment effects and (ii) better target patients who may benefit from treatments.

10.
Trials ; 20(1): 275, 2019 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-31109343

RESUMO

BACKGROUND: Inappropriate staff behaviour during surgical procedures may disrupt the surgical performance and compromise patient safety. We developed an innovative monitoring and feedback system combined with an adaptive approach to optimise staff behaviour intraoperatively and prevent post-operative complications (POC) in orthopaedic surgery. METHODS/DESIGN: This protocol describes a parallel-group, cluster randomised, controlled trial with orthopaedic centre as the unit of randomisation. The intervention period will last 6 months and will be based on the monitoring of two surrogates of staff behaviour: the frequency of doors opening and the level of noise. Both will be collected from incision to wound closure, using wireless sensors and sonometers, and recorded and analysed on a dedicated platform (Livepulse®). Staff from centres randomised to the intervention arm will be informed in real time on their own data through an interactive dashboard available in each operating room (OR), and a posteriori for hip and knee replacement POC. Aggregated data from all centres will also be displayed for benchmarking. A lean method will be applied in each centre by a local multidisciplinary team to analyse baseline situations, determine the target condition, analyse the root cause(s), and take countermeasures. The education and awareness of participants on the impact of their behaviour on patient safety will assist the quality improvement process. The control centres will be blinded to monitoring data and quality improvement approaches. The primary outcome will be any POC occurring during the 30 days post operation. We will evaluate this outcome using local and national routinely collected data from hospital discharge and disease databases. Thirty orthopaedic centres will be randomised for a total of 9945 hip and knee replacement surgical procedures. DISCUSSION: The field of human factors and behaviour in the OR seems to offer potential room for improvement. An intervention providing goal-setting, monitoring, feedback and action planning may reduce the traffic flow and interruptions/distractions of the surgical team during procedures, preventing subsequent POCs. The results of this trial will provide important data on the impact of OR staff behaviour on patient safety, and promote best practice during surgical procedures. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03158181 .


Assuntos
Artroplastia de Quadril/efeitos adversos , Artroplastia do Joelho/efeitos adversos , Corpo Clínico Hospitalar/psicologia , Complicações Pós-Operatórias/prevenção & controle , Ensaios Clínicos Controlados Aleatórios como Assunto , Análise por Conglomerados , Humanos , Salas Cirúrgicas , Avaliação de Resultados em Cuidados de Saúde , Segurança do Paciente , Melhoria de Qualidade , Tamanho da Amostra
12.
Anaesth Crit Care Pain Med ; 38(1): 15-23, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-29902538

RESUMO

INTRODUCTION: In elderly patients, goal-directed haemodynamic therapy (GDHT), depth of anaesthesia monitoring and lung-protective ventilation have been shown to improve postoperative outcomes. The aim of this study was to evaluate current practices concerning strategies of anaesthesia optimisation in patients aged≥75 years. PATIENTS AND METHODS: A multicentre observational study was performed from February to May 2015 in 23 French academic centres. On 30 consecutive days in each centre, patients≥75 years with at least one major comorbidity undergoing elective or emergency procedures (femoral-neck fractures surgery, intraperitoneal abdominal surgery or vascular surgery) were included. Patient characteristics and data related to GHDT, management of hypotension, monitoring of temperature and depth of anaesthesia, lung ventilation, point of care haemoglobin testing were collected. RESULTS: In total, 807 patients were included. Only 2% of patients [95% CI: 1-3] received GHDT in full accordance with guidelines. Depth of anaesthesia monitoring was largely performed (53% [95% CI: 50-56]). The multifaceted strategy of lung-protective ventilation combining low tidal volumes (6-8mL/kg), PEEP of 5-8cm cmH2O, and repeated recruitment manoeuvres, was performed in only 4% [95% CI: 3-5] of patients. A centre effect was a major determinant of variation concerning implementation of these strategies. DISCUSSION: In patients'≥75 years, strategies of anaesthesia optimisation are not in accordance with eligible guidelines. Implementation of these techniques varies independently of factors related to the patient or the type of surgery and may be dependent on the generated constraints.


Assuntos
Anestesia Geral/métodos , Fidelidade a Diretrizes , Hemodinâmica , Complicações Pós-Operatórias/prevenção & controle , Respiração Artificial/métodos , Abdome/cirurgia , Idoso , Idoso de 80 Anos ou mais , Anestesia Geral/efeitos adversos , Anestesia Geral/normas , Temperatura Corporal , Débito Cardíaco , Comorbidade , Procedimentos Cirúrgicos Eletivos , Eletroencefalografia/métodos , Serviços Médicos de Emergência , Fraturas do Colo Femoral/cirurgia , França , Fidelidade a Diretrizes/estatística & dados numéricos , Monitorização Hemodinâmica/métodos , Humanos , Hipotensão/terapia , Respiração com Pressão Positiva , Estudos Prospectivos , Respiração Artificial/estatística & dados numéricos , Volume de Ventilação Pulmonar , Procedimentos Cirúrgicos Vasculares
13.
Crit Care Med ; 47(3): 456-462, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30394920

RESUMO

OBJECTIVES: The Fragility Index, which represents the number of patients responsible for a statistically significant finding, has been suggested as an aid for interpreting the robustness of results from clinical trials. A small Fragility Index indicates that the statistical significance of a trial depends on only a few events. Our objectives were to calculate the Fragility Index of statistically significant results from randomized controlled trials of anesthesia and critical care interventions and to determine the frequency of distorted presentation of results or "spin". DATA SOURCES: We systematically searched MEDLINE from January 01, 2007, to February 22, 2017, to identify randomized controlled trials exploring the effect of critical care medicine or anesthesia interventions. STUDY SELECTION: Studies were included if they randomized patients 1:1 into two parallel arms and reported at least one statistically significant (p < 0.05) binary outcome (primary or secondary). DATA EXTRACTION: Two reviewers independently assessed eligibility and extracted data. The Fragility Index was determined for the chosen outcome. We assessed the level of spin in negative trials and the presence of recommendations for clinical practice in positive trials. DATA SYNTHESIS: We identified 166 eligible randomized controlled trials with a median sample size of 207 patients (interquartile range, 109-497). The median Fragility Index was 3 (interquartile range, 1-7), which means that adding three events to one of the trials treatment arms eliminated its statistical significance. High spin was identified in 42% (n = 30) of negative randomized controlled trials, whereas 21% (n = 20) of positive randomized controlled trials provided recommendations. Lower levels of spin and recommendations were associated with publication in journals with high impact factors (p < 0.001 for both). CONCLUSIONS: Statistically significant results in anesthesia and critical care randomized controlled trials are often fragile, and study conclusions are frequently affected by spin. Routine calculation of the Fragility Index in medical literature may allow for better understanding of trials and therefore enhance the quality of reporting.


Assuntos
Anestesia/métodos , Cuidados Críticos/métodos , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Anestesia/normas , Cuidados Críticos/normas , Interpretação Estatística de Dados , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto/normas , Reprodutibilidade dos Testes
14.
Can J Cardiol ; 34(7): 850-862, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29960614

RESUMO

Worldwide, more than 230 million adults have major noncardiac surgery each year. Although surgery can improve quality and duration of life, it can also precipitate major complications. Moreover, a substantial proportion of deaths occur after discharge. Current systems for monitoring patients postoperatively, on surgical wards and after transition to home, are inadequate. On the surgical ward, vital signs evaluation usually occurs only every 4-8 hours. Reduced in-hospital ward monitoring, followed by no vital signs monitoring at home, leads to thousands of cases of undetected/delayed detection of hemodynamic compromise. In this article we review work to date on postoperative remote automated monitoring on surgical wards and strategy for advancing this field. Key considerations for overcoming current barriers to implementing remote automated monitoring in Canada are also presented.


Assuntos
Monitorização Fisiológica/métodos , Cuidados Pós-Operatórios/métodos , Procedimentos Cirúrgicos Operatórios , Telemedicina/métodos , Sinais Vitais/fisiologia , Humanos
15.
Can J Surg ; 61(3): 185-194, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29806816

RESUMO

BACKGROUND: Myocardial injury after noncardiac surgery (MINS) is a mostly asymptomatic condition that is strongly associated with 30-day mortality; however, it remains mostly undetected without systematic troponin T monitoring. We evaluated the cost and consequences of postoperative troponin T monitoring to detect MINS. METHODS: We conducted a model-based cost-consequence analysis to compare the impact of routine troponin T monitoring versus standard care (troponin T measurement triggered by ischemic symptoms) on the incidence of MINS detection. Model inputs were based on Canadian patients enrolled in the Vascular Events in Noncardiac Surgery Patients Cohort Evaluation (VISION) study, which enrolled patients aged 45 years or older undergoing inpatient noncardiac surgery. We conducted probability analyses with 10 000 iterations and extensive sensitivity analyses. RESULTS: The data were based on 6021 patients (48% men, mean age 65 [standard deviation 12] yr). The 30-day mortality rate for MINS was 9.6%. We determined the incremental cost to avoid missing a MINS event as $1632 (2015 Canadian dollars). The cost-effectiveness of troponin monitoring was higher in patient subgroups at higher risk for MINS, e.g., those aged 65 years or more, or with a history of atherosclerosis or diabetes ($1309). CONCLUSION: The costs associated with a troponin T monitoring program to detect MINS were moderate. Based on the estimated incremental cost per health gain, implementation of postoperative troponin T monitoring seems appealing, particularly in patients at high risk for MINS.


Assuntos
Análise Custo-Benefício , Isquemia Miocárdica , Avaliação de Resultados em Cuidados de Saúde , Cuidados Pós-Operatórios , Complicações Pós-Operatórias , Procedimentos Cirúrgicos Operatórios/efeitos adversos , Troponina T/sangue , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/sangue , Isquemia Miocárdica/diagnóstico , Isquemia Miocárdica/economia , Isquemia Miocárdica/mortalidade , Avaliação de Resultados em Cuidados de Saúde/economia , Cuidados Pós-Operatórios/economia , Cuidados Pós-Operatórios/métodos , Cuidados Pós-Operatórios/normas , Complicações Pós-Operatórias/sangue , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/economia , Complicações Pós-Operatórias/mortalidade , Risco
16.
J Am Geriatr Soc ; 66(6): 1151-1157, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29676780

RESUMO

OBJECTIVES: To compare the association between a restrictive transfusion strategy and cardiovascular complications during hospitalization for hip fracture with the association between a liberal transfusion strategy and cardiovascular complications, accounting for all transfusions from the emergency department to postacute rehabilitation settings. DESIGN: Retrospective study. SETTING: Perioperative geriatric care unit. PARTICIPANTS: All individuals aged 70 and older admitted to the emergency department for hip fracture and hospitalized in our perioperative geriatric care unit (N=667; n=193 in the liberal transfusion group, n=474 in the restrictive transfusion group) from July 2009 to April 2016. INTERVENTION: A restrictive transfusion strategy (hemoglobin level threshold ≥8 g/dL or symptoms) used from January 2012 to April 2016 was compared with the liberal transfusion strategy (hemoglobin level threshold ≥10 g/dL) used from July 2009 to December 2011. MEASUREMENTS: Primary endpoint was in-hospital acute cardiovascular complications (heart failure, myocardial infarction, atrial fibrillation or stroke). RESULTS: The change to a restrictive transfusion strategy was associated with fewer acute cardiovascular complications (odds ratio=0.45, 95% confidence interval (CI)=0.31-0.67, p<.001), without any noticeable difference in in-hospital or 6-month mortality. The change also led to a reduction in packed red blood cell units used per participant (median 1, interquartile range (IQR) 0-2 in restrictive vs median 2, IQR 0-3 in liberal transfusion strategy, P<.001). In rehabilitation settings, the frequency of transfusion was greater with the restrictive transfusion strategy than the liberal transfusion strategy (18% vs 9%, P<.001). CONCLUSION: A restrictive transfusion strategy in older adults with hip fracture was found to be safe and was associated with fewer cardiovascular complications but more transfusions in rehabilitation settings. Prospective studies are needed to confirm these findings.


Assuntos
Anemia/terapia , Transfusão de Sangue , Doenças Cardiovasculares , Fixação de Fratura/efeitos adversos , Assistência Perioperatória , Complicações Pós-Operatórias , Idoso , Anemia/diagnóstico , Anemia/etiologia , Transfusão de Sangue/métodos , Transfusão de Sangue/estatística & dados numéricos , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/prevenção & controle , Feminino , Fixação de Fratura/reabilitação , França/epidemiologia , Avaliação Geriátrica/métodos , Fraturas do Quadril/cirurgia , Humanos , Masculino , Assistência Perioperatória/efeitos adversos , Assistência Perioperatória/métodos , Assistência Perioperatória/estatística & dados numéricos , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/terapia , Estudos Retrospectivos
17.
Ann Intern Med ; 168(4): 237-244, 2018 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-29132159

RESUMO

Background: Uncertainty remains about the effects of aspirin in patients with prior percutaneous coronary intervention (PCI) having noncardiac surgery. Objective: To evaluate benefits and harms of perioperative aspirin in patients with prior PCI. Design: Nonprespecified subgroup analysis of a multicenter factorial trial. Computerized Internet randomization was done between 2010 and 2013. Patients, clinicians, data collectors, and outcome adjudicators were blinded to treatment assignment. (ClinicalTrials.gov: NCT01082874). Setting: 135 centers in 23 countries. Patients: Adults aged 45 years or older who had or were at risk for atherosclerotic disease and were having noncardiac surgery. Exclusions were placement of a bare-metal stent within 6 weeks, placement of a drug-eluting stent within 1 year, or receipt of nonstudy aspirin within 72 hours before surgery. Intervention: Aspirin therapy (overall trial, n = 4998; subgroup, n = 234) or placebo (overall trial, n = 5012; subgroup, n = 236) initiated within 4 hours before surgery and continued throughout the perioperative period. Of the 470 subgroup patients, 99.9% completed follow-up. Measurements: The 30-day primary outcome was death or nonfatal myocardial infarction; bleeding was a secondary outcome. Results: In patients with prior PCI, aspirin reduced the risk for the primary outcome (absolute risk reduction, 5.5% [95% CI, 0.4% to 10.5%]; hazard ratio [HR], 0.50 [CI, 0.26 to 0.95]; P for interaction = 0.036) and for myocardial infarction (absolute risk reduction, 5.9% [CI, 1.0% to 10.8%]; HR, 0.44 [CI, 0.22 to 0.87]; P for interaction = 0.021). The effect on the composite of major and life-threatening bleeding in patients with prior PCI was uncertain (absolute risk increase, 1.3% [CI, -2.6% to 5.2%]). In the overall population, aspirin increased the risk for major bleeding (absolute risk increase, 0.8% [CI, 0.1% to 1.6%]; HR, 1.22 [CI, 1.01 to 1.48]; P for interaction = 0.50). Limitation: Nonprespecified subgroup analysis with small sample. Conclusion: Perioperative aspirin may be more likely to benefit rather than harm patients with prior PCI. Primary Funding Source: Canadian Institutes of Health Research.


Assuntos
Aspirina/uso terapêutico , Intervenção Coronária Percutânea , Inibidores da Agregação de Plaquetas/uso terapêutico , Procedimentos Cirúrgicos Operatórios , Idoso , Anti-Hipertensivos/uso terapêutico , Aspirina/efeitos adversos , Biomarcadores/sangue , Clonidina/uso terapêutico , Esquema de Medicação , Quimioterapia Combinada , Feminino , Hemorragia/induzido quimicamente , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/prevenção & controle , Inibidores da Agregação de Plaquetas/efeitos adversos , Complicações Pós-Operatórias/induzido quimicamente , Complicações Pós-Operatórias/prevenção & controle , Resultado do Tratamento
18.
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.

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