183 resultados para Trials (Impeachment)


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BACKGROUND Overlapping first generation sirolimus- and paclitaxel-eluting stents are associated with persistent inflammation, fibrin deposition and delayed endothelialisation in preclinical models, and adverse angiographic and clinical outcomes--including death and myocardial infarction (MI)--in clinical studies. OBJECTIVES To establish as to whether there are any safety concerns with newer generation drug-eluting stents (DES). DESIGN Propensity score adjustment of baseline anatomical and clinical characteristics were used to compare clinical outcomes (Kaplan-Meier estimates) between patients implanted with overlapping DES (Resolute zotarolimus-eluting stent (R-ZES) or R-ZES/other DES) against no overlapping DES. Additionally, angiographic outcomes for overlapping R-ZES and everolimus-eluting stents were evaluated in the randomised RESOLUTE All-Comers Trial. SETTING Patient level data from five controlled studies of the RESOLUTE Global Clinical Program evaluating the R-ZES were pooled. Enrollment criteria were generally unrestrictive. PATIENTS 5130 patients. MAIN OUTCOME MEASURES 2-year clinical outcomes and 13-month angiographic outcomes. RESULTS 644 of 5130 patients (12.6%) in the RESOLUTE Global Clinical Program underwent overlapping DES implantation. Implantation of overlapping DES was associated with an increased frequency of MI and more complex/calcified lesion types at baseline. Adjusted in-hospital, 30-day and 2-year clinical outcomes indicated comparable cardiac death (2-year overlap vs non-overlap: 3.0% vs 2.1%, p=0.36), major adverse cardiac events (13.3% vs 10.7%, p=0.19), target-vessel MI (3.9% vs 3.4%, p=0.40), clinically driven target vessel revascularisation (7.7% vs 6.5%, p=0.32), and definite/probable stent thrombosis (1.4% vs 0.9%, p=0.28). 13-month adjusted angiographic outcomes were comparable between overlapping and non-overlapping DES. CONCLUSIONS Overlapping newer generation DES are safe and effective, with comparable angiographic and clinical outcomes--including repeat revascularisation--to non-overlapping DES.

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BACKGROUND The optimal schedule and the need for a booster dose are unclear for Haemophilus influenzae type b (Hib) conjugate vaccines. We systematically reviewed relative effects of Hib vaccine schedules. METHODS We searched 21 databases to May 2010 or June 2012 and selected randomized controlled trials or quasi-randomized controlled trials that compared different Hib schedules (3 primary doses with no booster dose [3p+0], 3p+1 and 2p+1) or different intervals in primary schedules and between primary and booster schedules. Outcomes were clinical efficacy, nasopharyngeal carriage and immunological response. Results were combined in random-effects meta-analysis. RESULTS Twenty trials from 15 countries were included; 16 used vaccines conjugated to tetanus toxoid (polyribosylribitol phosphate conjugated to tetanus toxoid). No trials assessed clinical or carriage outcomes. Twenty trials examined immunological outcomes and found few relevant differences. Comparing polyribosylribitol phosphate conjugated to tetanus toxoid 3p+0 with 2p+0, there was no difference in seropositivity at the 1.0 μg/mL threshold by 6 months after the last primary dose (combined risk difference -0.02; 95% confidence interval: -0.10, 0.06). Only small differences were seen between schedules starting at different ages, with different intervals between primary doses, or with different intervals between primary and booster doses. Individuals receiving a booster were more likely to be seropositive than those at the same age who did not. CONCLUSIONS There is no clear evidence from trials that any 2p+1, 3p+0 or 3p+1 schedule of Hib conjugate vaccine is likely to provide better protection against Hib disease than other schedules. Until more data become available, scheduling is likely to be determined by epidemiological and programmatic considerations in individual settings.

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Schizophrenia is still associated with poor outcome, which is mainly related to negative symptoms, reduced physical activity and low quality of life. Physical activity can be objectively measured without distress using wrist actigraphy. The activity levels during the wake periods of the day have been informative on psychopathology and antipsychotic medication. Several studies demonstrated prominent negative symptoms to be associated with reduced activity levels with strongest correlations in chronic patients. Particularly, the avolition score is correlated with reduced activity levels. Moreover, activity levels differ between DSM-IV schizophrenia spectrum disorders and subtypes as well as between patients treated with olanzapine or risperidone. The longitudinal course of activity levels during an psychotic episode demonstrates considerable variance between subjects. During a psychotic episode patients with low activity levels at baseline experience an amelioration of negative symptoms. In contrast, patients with high activity levels at baseline have stable low negative syndrome scores. Between psychotic episodes less variance is observed. Actigraphy is easily applied in schizophrenia and allows collecting large amounts of crosssectional or longitudinal data. With larger numbers of subjects in controlled trials, continuous recording of activity would foster the detection of different outcome trajectories, which may prove as useful groups to target interventions. In clinical trials, activity monitoring may supplement and validate measures of the negative syndrome and its avolition factor or serve as an outcome marker for physical activity, which is important for metabolic issues and quality of life.

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OBJECTIVES Although the use of an adjudication committee (AC) for outcomes is recommended in randomized controlled trials, there are limited data on the process of adjudication. We therefore aimed to assess whether the reporting of the adjudication process in venous thromboembolism (VTE) trials meets existing quality standards and which characteristics of trials influence the use of an AC. STUDY DESIGN AND SETTING We systematically searched MEDLINE and the Cochrane Library from January 1, 2003, to June 1, 2012, for randomized controlled trials on VTE. We abstracted information about characteristics and quality of trials and reporting of adjudication processes. We used stepwise backward logistic regression model to identify trial characteristics independently associated with the use of an AC. RESULTS We included 161 trials. Of these, 68.9% (111 of 161) reported the use of an AC. Overall, 99.1% (110 of 111) of trials with an AC used independent or blinded ACs, 14.4% (16 of 111) reported how the adjudication decision was reached within the AC, and 4.5% (5 of 111) reported on whether the reliability of adjudication was assessed. In multivariate analyses, multicenter trials [odds ratio (OR), 8.6; 95% confidence interval (CI): 2.7, 27.8], use of a data safety-monitoring board (OR, 3.7; 95% CI: 1.2, 11.6), and VTE as the primary outcome (OR, 5.7; 95% CI: 1.7, 19.4) were associated with the use of an AC. Trials without random allocation concealment (OR, 0.3; 95% CI: 0.1, 0.8) and open-label trials (OR, 0.3; 95% CI: 0.1, 1.0) were less likely to report an AC. CONCLUSION Recommended processes of adjudication are underreported and lack standardization in VTE-related clinical trials. The use of an AC varies substantially by trial characteristics.

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Future clinical trials investigating the natural history and treatment of femoroacetabular impingement (FAI) will require multimodal staging systems for hip osteoarthritis because the optimal system will differ based on the size of the study population, the specific objective in question, and the time frame in which the investigator expects to see the specified end point. Plain radiographs are readily available, low in cost, and of unquestioned validity, but they are relatively insensitive to early joint damage. MRI allows assessment of both bony and soft-tissue pathology within the joint, and it is much more sensitive for early joint damage because cartilage is visualized directly. Biochemical imaging techniques such as delayed gadolinium-enhanced MRI of cartilage, T2 mapping, and T1rho offer the potential to identify biochemical damage to cartilage before the onset of irreversible tissue loss. In the future, biomarkers may allow earlier detection of osteoarthritis before the development of radiographic evidence of disease.

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OBJECTIVES In 2003 the International Breast Cancer Study Group (IBCSG) initiated the TEXT and SOFT randomized phase III trials to answer two questions concerning adjuvant treatment for premenopausal women with endocrine-responsive early breast cancer: 1-What is the role of aromatase inhibitors (AI) for women treated with ovarian function suppression (OFS)? 2-What is the role of OFS for women who remain premenopausal and are treated with tamoxifen? METHODS TEXT randomized patients to receive exemestane or tamoxifen with OFS. SOFT randomized patients to receive exemestane with OFS, tamoxifen with OFS, or tamoxifen alone. Treatment was for 5 years from randomization. RESULTS TEXT and SOFT successfully met their enrollment goals in 2011. The 5738 enrolled women had lower-risk disease and lower observed disease-free survival (DFS) event rates than anticipated. Consequently, 7 and 13 additional years of follow-up for TEXT and SOFT, respectively, were required to reach the targeted DFS events (median follow-up about 10.5 and 15 years). To provide timely answers, protocol amendments in 2011 specified analyses based on chronological time and median follow-up. To assess the AI question, exemestane + OFS versus tamoxifen + OFS, a combined analysis of TEXT and SOFT became the primary analysis (n = 4717). The OFS question became the primary analysis from SOFT, assessing the unique comparison of tamoxifen + OFS versus tamoxifen alone (n = 2045). The first reports are anticipated in mid- and late-2014. CONCLUSIONS We present the original designs of TEXT and SOFT and adaptations to ensure timely answers to two questions concerning optimal adjuvant endocrine treatment for premenopausal women with endocrine-responsive breast cancer. Trial Registration TEXT: Clinicaltrials.govNCT00066703 SOFT: Clinicaltrials.govNCT00066690.

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Aims: Arterial plaque rupture and thrombus characterise ST-elevation myocardial infarction (STEMI) and may aggravate delayed arterial healing following durable polymer drug-eluting stent (DP-DES) implantation. Biodegradable polymer (BP) may improve biocompatibility. We compared long-term outcomes in STEMI patients receiving BP-DES vs. durable polymer sirolimus-eluting stents (DP-SES). Methods and results: We pooled individual patient-level data from three randomised clinical trials (ISAR-TEST-3, ISAR-TEST-4 and LEADERS) comparing outcomes from BP-DES with DP-SES at four years. The primary endpoint (MACE) comprised cardiac death, MI, or target lesion revascularisation (TLR). Secondary endpoints were TLR, cardiac death or MI, and definite or probable stent thrombosis. Of 497 patients with STEMI, 291 received BP-DES and 206 DP-SES. At four years, MACE was significantly reduced following treatment with BP-DES (hazard ratio [HR] 0.59, 95% CI: 0.39-0.90; p=0.01) driven by reduced TLR (HR 0.54, 95% CI: 0.30-0.98; p=0.04). Trends towards reduction were seen for cardiac death or MI (HR 0.63, 95% CI: 0.37-1.05; p=0.07) and definite or probable stent thrombosis (3.6% vs. 7.1%; HR 0.49, 95% CI: 0.22-1.11; p=0.09). Conclusions: In STEMI, BP-DES demonstrated superior clinical outcomes to DP-SES at four years. Trends towards reduced cardiac death or myocardial infarction and reduced stent thrombosis require corroboration in specifically powered trials.

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BACKGROUND Randomized control trials (RCTs) stopped early for benefit (truncated RCTs) are increasingly common and, on average, overestimate the relative magnitude of benefit by approximately 30%. Investigators stop trials early when they consider it is no longer ethical to enroll patients in a control group. The goal of this systematic review is to determine how investigators of ongoing or planned RCTs respond to the publication of a truncated RCT addressing a similar question. METHODS/DESIGN We will conduct systematic reviews to update the searches of 210 truncated RCTs to identify similar trials ongoing at the time of publication, or started subsequently, to the truncated trials ('subsequent RCTs'). Reviewers will determine in duplicate the similarity between the truncated and subsequent trials. We will analyze the epidemiology, distribution, and predictors of subsequent RCTs. We will also contact authors of subsequent trials to determine reasons for beginning, continuing, or prematurely discontinuing their own trials, and the extent to which they rely on the estimates from truncated trials. DISCUSSION To the extent that investigators begin or continue subsequent trials they implicitly disagree with the decision to stop the truncated RCT because of an ethical mandate to administer the experimental treatment. The results of this study will help guide future decisions about when to stop RCTs early for benefit.

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OBJECTIVES Endovascular therapy is a rapidly expanding option for the treatment of patients with aortic dissection (AD) and various studies have been published. These trials, however, are often difficult to interpret and compare because they do not utilize uniform clinical endpoint definitions. METHODS The DEFINE Group is a collaborative effort of an ad hoc multidisciplinary team from various specialties involved in AD therapy in Europe and the United States. DEFINE's goal was to arrive at a broad based consensus for baseline and endpoint definitions in trials for endovascular therapy of various vascular pathologies. In this project, which started in December 2006, the individual team members reviewed the existing pertinent literature. Following this, a series of telephone conferences and face-to-face meetings were held to agree upon definitions. Input was also obtained from regulatory (United States Food and Drug Administration) and industry (device manufacturers with an interest in peripheral endovascular revascularization) stakeholders, respectively. RESULTS These efforts resulted in the present document containing proposed baseline and endpoint definitions for clinical and morphological outcomes. Although the consensus has inevitably included certain arbitrary consensus choices and compromises, adherence to these proposed standard definitions would provide consistency across future trials, thereby facilitating evaluation of clinical effectiveness and safety of various endovascular revascularization techniques. CONCLUSIONS This current document is based on a broad based consensus involving relevant stakeholders from the medical community, industry and regulatory bodies. It is proposed that the consensus document may have value for study design of future clinical trials in endovascular AD therapy as well as for regulatory purposes.

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OBJECTIVES To test the inter-rater reliability of the RoB tool applied to Physical Therapy (PT) trials by comparing ratings from Cochrane review authors with those of blinded external reviewers. METHODS Randomized controlled trials (RCTs) in PT were identified by searching the Cochrane Database of Systematic Reviews for meta-analysis of PT interventions. RoB assessments were conducted independently by 2 reviewers blinded to the RoB ratings reported in the Cochrane reviews. Data on RoB assessments from Cochrane reviews and other characteristics of reviews and trials were extracted. Consensus assessments between the two reviewers were then compared with the RoB ratings from the Cochrane reviews. Agreement between Cochrane and blinded external reviewers was assessed using weighted kappa (κ). RESULTS In total, 109 trials included in 17 Cochrane reviews were assessed. Inter-rater reliability on the overall RoB assessment between Cochrane review authors and blinded external reviewers was poor (κ  =  0.02, 95%CI: -0.06, 0.06]). Inter-rater reliability on individual domains of the RoB tool was poor (median κ  = 0.19), ranging from κ  =  -0.04 ("Other bias") to κ  =  0.62 ("Sequence generation"). There was also no agreement (κ  =  -0.29, 95%CI: -0.81, 0.35]) in the overall RoB assessment at the meta-analysis level. CONCLUSIONS Risk of bias assessments of RCTs using the RoB tool are not consistent across different research groups. Poor agreement was not only demonstrated at the trial level but also at the meta-analysis level. Results have implications for decision making since different recommendations can be reached depending on the group analyzing the evidence. Improved guidelines to consistently apply the RoB tool and revisions to the tool for different health areas are needed.

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Aims: The aim of this study was to identify predictors of adverse events among patients with ST-elevation myocardial infarction (STEMI) undergoing contemporary primary percutaneous coronary intervention (PCI). Methods and results: Individual data of 2,655 patients from two primary PCI trials (EXAMINATION, N=1,504; COMFORTABLE AMI, N=1,161) with identical endpoint definitions and event adjudication were pooled. Predictors of all-cause death or any reinfarction and definite stent thrombosis (ST) and target lesion revascularisation (TLR) outcomes at one year were identified by multivariable Cox regression analysis. Killip class III or IV was the strongest predictor of all-cause death or any reinfarction (OR 5.11, 95% CI: 2.48-10.52), definite ST (OR 7.74, 95% CI: 2.87-20.93), and TLR (OR 2.88, 95% CI: 1.17-7.06). Impaired left ventricular ejection fraction (OR 4.77, 95% CI: 2.10-10.82), final TIMI flow 0-2 (OR 1.93, 95% CI: 1.05-3.54), arterial hypertension (OR 1.69, 95% CI: 1.11-2.59), age (OR 1.68, 95% CI: 1.41-2.01), and peak CK (OR 1.25, 95% CI: 1.02-1.54) were independent predictors of all-cause death or any reinfarction. Allocation to treatment with DES was an independent predictor of a lower risk of definite ST (OR 0.35, 95% CI: 0.16-0.74) and any TLR (OR 0.34, 95% CI: 0.21-0.54). Conclusions: Killip class remains the strongest predictor of all-cause death or any reinfarction among STEMI patients undergoing primary PCI. DES use independently predicts a lower risk of TLR and definite ST compared with BMS. The COMFORTABLE AMI trial is registered at: http://www.clinicaltrials.gov/ct2/show/NCT00962416. The EXAMINATION trial is registered at: http://www.clinicaltrials.gov/ct2/show/NCT00828087.

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BACKGROUND: Musculoskeletal disorders, stress and performance anxiety are common in musicians. Therefore, some use the Alexander Technique (AT), a psycho-physical method that helps to release unnecessary muscle tension and re-educates non-beneficial movement patterns through intentional inhibition of unwanted habitual behaviours. According to a recent review AT sessions may be effective for chronic back pain. This review aimed to evaluate the evidence for the effectiveness of AT sessions on musicians' performance, anxiety, respiratory function and posture. METHODS: The following electronic databases were searched up to February 2014 for relevant publications: PUBMED, Google Scholar, CINAHL, EMBASE, AMED, PsycINFO and RILM. The search criteria were "Alexander Technique" AND "music*". References were searched, and experts and societies of AT or musicians' medicine contacted for further publications. RESULTS: 237 citations were assessed. 12 studies were included for further analysis, 5 of which were randomised controlled trials (RCTs), 5 controlled but not randomised (CTs), and 2 mixed methods studies. Main outcome measures in RCTs and CTs were music performance, respiratory function, performance anxiety, body use and posture. Music performance was judged by external experts and found to be improved by AT in 1 of 3 RCTs; in 1 RCT comparing neurofeedback (NF) to AT, only NF caused improvements. Respiratory function was investigated in 2 RCTs, but not improved by AT training. Performance anxiety was mostly assessed by questionnaires and decreased by AT in 2 of 2 RCTs and in 2 of 2 CTs. CONCLUSIONS: A variety of outcome measures have been used to investigate the effectiveness of AT sessions in musicians. Evidence from RCTs and CTs suggests that AT sessions may improve performance anxiety in musicians. Effects on music performance, respiratory function and posture yet remain inconclusive. Future trials with well-established study designs are warranted to further and more reliably explore the potential of AT in the interest of musicians.

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Historical information is always relevant for clinical trial design. Additionally, if incorporated in the analysis of a new trial, historical data allow to reduce the number of subjects. This decreases costs and trial duration, facilitates recruitment, and may be more ethical. Yet, under prior-data conflict, a too optimistic use of historical data may be inappropriate. We address this challenge by deriving a Bayesian meta-analytic-predictive prior from historical data, which is then combined with the new data. This prospective approach is equivalent to a meta-analytic-combined analysis of historical and new data if parameters are exchangeable across trials. The prospective Bayesian version requires a good approximation of the meta-analytic-predictive prior, which is not available analytically. We propose two- or three-component mixtures of standard priors, which allow for good approximations and, for the one-parameter exponential family, straightforward posterior calculations. Moreover, since one of the mixture components is usually vague, mixture priors will often be heavy-tailed and therefore robust. Further robustness and a more rapid reaction to prior-data conflicts can be achieved by adding an extra weakly-informative mixture component. Use of historical prior information is particularly attractive for adaptive trials, as the randomization ratio can then be changed in case of prior-data conflict. Both frequentist operating characteristics and posterior summaries for various data scenarios show that these designs have desirable properties. We illustrate the methodology for a phase II proof-of-concept trial with historical controls from four studies. Robust meta-analytic-predictive priors alleviate prior-data conflicts ' they should encourage better and more frequent use of historical data in clinical trials.

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Factorial designs for clinical trials are often encountered in medical, dental, and orthodontic research. Factorial designs assess two or more interventions simultaneously and the main advantage of this design is its efficiency in terms of sample size as more than one intervention may be assessed on the same participants. However, the factorial design is efficient only under the assumption of no interaction (no effect modification) between the treatments under investigation and, therefore, this should be considered at the design stage. Conversely, the factorial study design may also be used for the purpose of detecting an interaction between two interventions if the study is powered accordingly. However, a factorial design powered to detect an interaction has no advantage in terms of the required sample size compared to a multi-arm parallel trial for assessing more than one intervention. It is the purpose of this article to highlight the methodological issues that should be considered when planning, analysing, and reporting the simplest form of this design, which is the 2 × 2 factorial design. An example from the field of orthodontics using two parameters (bracket type and wire type) on maxillary incisor torque loss will be utilized in order to explain the design requirements, the advantages and disadvantages of this design, and its application in orthodontic research.