529 research outputs found

    Rationale for key elements of Sino-American collaboration in clinical research

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    Trial Registration for Public Trust: Making the Case for Medical Devices

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    Recently, several pharmaceutical companies have been shown to have withheld negative clinical trial results from the public. These incidents have resulted in a concerted global effort to register all trials at inception, so that all subsequent results can be tracked regardless of whether they are positive or negative. These trial registration policies have been driven in large part by concern about the pharmaceutical sector. The medical device industry is much smaller, and different from the pharmaceutical industry in some fundamental ways. This paper examines the issues surrounding registration of device trials and argues that these differences with pharmaceutical should not exempt device trials from registration

    Design and rationale of a multi-center, pragmatic, open-label randomized trial of antimicrobial therapy - the study of clinical efficacy of antimicrobial therapy strategy using pragmatic design in Idiopathic Pulmonary Fibrosis (CleanUP-IPF) clinical trial

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    Compelling data have linked disease progression in patients with idiopathic pulmonary fibrosis (IPF) with lung dysbiosis and the resulting dysregulated local and systemic immune response. Moreover, prior therapeutic trials have suggested improved outcomes in these patients treated with either sulfamethoxazole/ trimethoprim or doxycycline. These trials have been limited by methodological concerns. This trial addresses the primary hypothesis that long-term treatment with antimicrobial therapy increases the time-to-event endpoint of respiratory hospitalization or all-cause mortality compared to usual care treatment in patients with IPF. We invoke numerous innovative features to achieve this goal, including: 1) utilizing a pragmatic randomized trial design; 2) collecting targeted biological samples to allow future exploration of 'personalized' therapy; and 3) developing a strong partnership between the NHLBI, a broad range of investigators, industry, and philanthropic organizations. The trial will randomize approximately 500 individuals in a 1:1 ratio to either antimicrobial therapy or usual care. The site principal investigator will declare their preferred initial antimicrobial treatment strategy (trimethoprim 160 mg/ sulfamethoxazole 800 mg twice a day plus folic acid 5 mg daily or doxycycline 100 mg once daily if body weight is < 50 kg or 100 mg twice daily if ≥50 kg) for the participant prior to randomization. Participants randomized to antimicrobial therapy will receive a voucher to help cover the additional prescription drug costs. Additionally, those participants will have 4-5 scheduled blood draws over the initial 24 months of therapy for safety monitoring. Blood sampling for DNA sequencing and genome wide transcriptomics will be collected before therapy. Blood sampling for transcriptomics and oral and fecal swabs for determination of the microbiome communities will be collected before and after study completion. As a pragmatic study, participants in both treatment arms will have limited in-person visits with the enrolling clinical center. Visits are limited to assessments of lung function and other clinical parameters at time points prior to randomization and at months 12, 24, and 36. All participants will be followed until the study completion for the assessment of clinical endpoints related to hospitalization and mortality events. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT02759120

    Atherosclerosis of the descending aorta predicts cardiovascular events: a transesophageal echocardiography study

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    PURPOSE: Previous studies have shown that atherosclerosis of the descending aorta detected by transesophageal echocardiography (TEE) is a good marker of coexisting coronary artery disease. The aim of our study was to evaluate whether the presence of atherosclerosis on the descending aorta during TEE has any prognostic impact in predicting cardiovascular events. MATERIAL AND METHODS: The study group consisted of 238 consecutive in-hospital patients referred for TEE testing (135 males, 103 females, mean age 58 +/- 11 years) with a follow up of 24 months. The atherosclerotic lesions of the descending aorta were scored from 0 (no atherosclerosis) to 3 (plaque >5 mm and/or "complex" plaque with ulcerated or mobile parts). RESULTS: Atherosclerosis was observed in 102 patients, (grade 3 in 16, and grade 2 in 86 patients) whereas 136 patients only had an intimal thickening or normal intimal surface. There were 57 cardiovascular events in the follow-up period. The number of events was higher in the 102 patients with (n = 34) than in the 136 patients without atherosclerosis (n = 23, p < 0.01). The frequency of events was in close correlation with the severity of the atherosclerosis of the descending aorta. Fifty percent of the patients with grade 3 experienced cardiovascular events. Excluding patients with subsequent revascularization, the multivariate analysis only left ventricular function with EF < 40% (HR 3.0, CI 1.3–7.1) and TEE atherosclerotic plaque >=2 (HR 2.4, CI 1.0–5.5) predicted hard cardiovascular events. CONCLUSION: Atherosclerosis of the descending aorta observed during transesophageal echocardiography is a useful predictor of cardiovascular events

    Testing for heterogeneity among the components of a binary composite outcome in a clinical trial

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    <p>Abstract</p> <p>Background</p> <p>Investigators designing clinical trials often use composite outcomes to overcome many statistical issues. Trialists want to maximize power to show a statistically significant treatment effect and avoid inflation of Type I error rate due to evaluation of multiple individual clinical outcomes. However, if the treatment effect is not similar among the components of this composite outcome, we are left not knowing how to interpret the treatment effect on the composite itself. Given significant heterogeneity among these components, a composite outcome may be judged as being invalid or un-interpretable for estimation of the treatment effect. This paper compares the power of different tests to detect heterogeneity of treatment effect across components of a composite binary outcome.</p> <p>Methods</p> <p>Simulations were done comparing four different models commonly used to analyze correlated binary data. These models included: logistic regression for ignoring correlation, logistic regression weighted by the intra cluster correlation coefficient, population average logistic regression using generalized estimating equations (GEE), and random effects logistic regression.</p> <p>Results</p> <p>We found that the population average model based on generalized estimating equations (GEE) had the greatest power across most scenarios. Adequate power to detect possible composite heterogeneity or variation between treatment effects of individual components of a composite outcome was seen when the power for detecting the main study treatment effect for the composite outcome was also reasonably high.</p> <p>Conclusions</p> <p>It is recommended that authors report tests of composite heterogeneity for composite outcomes and that this accompany the publication of the statistically significant results of the main effect on the composite along with individual components of composite outcomes.</p

    Delphi-Consensus Weights for Ischemic and Bleeding Events to Be Included in a Composite Outcome for RCTs in Thrombosis Prevention

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    To weight ischemic and bleeding events according to their severity to be used in a composite outcome in RCTs in the field of thrombosis prevention.Using a Delphi consensus method, a panel of anaesthesiology and cardiology experts rated the severity of thrombotic and bleeding clinical events. The ratings were expressed on a 10-point scale. The median and quartiles of the ratings of each item were returned to the experts. Then, the panel members evaluated the events a second time with knowledge of the group responses from the first round. Cronbach's a was used as a measure of homogeneity for the ratings. The final rating for each event corresponded to the median rating obtained at the last Delphi round.Of 70 experts invited, 32 (46%) accepted to participate. Consensus was reached at the second round as indicated by Cronbach's a value (0.99 (95% CI 0.98-1.00)) so the Delphi was stopped. Severity ranged from under-popliteal venous thrombosis (median = 3, Q1 = 2; Q3 = 3) to ischemic stroke or intracerebral hemorrhage with severe disability at 7 days and massive pulmonary embolism (median = 9, Q1 = 9; Q3 = 9). Ratings did not differ according to the medical specialty of experts.These ratings could be used to weight ischemic and bleeding events of various severity comprising a composite outcome in the field of thrombosis prevention
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