Event Rates in Randomized Clinical Trials Evaluating Cardiovascular Interventions and Devices

2015 ◽  
Vol 116 (3) ◽  
pp. 355-363 ◽  
Author(s):  
Karim D. Mahmoud ◽  
Ryan J. Lennon ◽  
David R. Holmes
Keyword(s):  
Clinical Trials ◽  
Randomized Clinical Trials ◽  
Cardiovascular Interventions ◽  
Event Rates

scholarly journals Baseline EDSS proportions in MS clinical trials affect the overall outcome and power: A cautionary note

2016 ◽  
Vol 23 (7) ◽  
pp. 982-987 ◽  
Author(s):  
Guoqiao Wang ◽  
Gary R Cutter ◽  
Stacey S Cofield ◽  
Fred Lublin ◽  
Jerry S Wolinsky ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Randomized Clinical Trials ◽  
Progression Rate ◽  
Disability Progression ◽  
Cautionary Note ◽  
Trial Outcome ◽  
Disability Status ◽  
Relapsing Remitting ◽  
Event Rates ◽  
Relapsing Remitting Multiple Sclerosis

Background: In randomized clinical trials, when treatments do not work equally effectively across stratifications of participants, observed event rates may differ from those hypothesized leading to deviations in estimated power. Objectives: To investigate the effect of distributions of baseline Expanded Disability Status Scale (EDSS) proportions in relapsing-remitting multiple sclerosis (RRMS) on the trial outcome, confirmed disability progression rate (CDPR), and power. Methods: We reported CDPRs in the CombiRx trial by baseline EDSS and by groups (1st (0, 1), 2nd (1.5, 2), 3rd (2.5, 3), and 4th (⩾3.5)) and investigated the effect of different combinations of baseline EDSS proportions on the trial outcome and power. Results: There were 244 (25.4%) participants in the 1st group, 368 (38.4%) in the 2nd group, 223 (23.3%) in the 3rd group, and 124 (12.9%) in the 4th group with CDPRs of 40.1%, 13.9%, 11.2%, and 16.9%, respectively. Both CDPR and power increased when the proportion of the 1st group increased in hypothetical trials with equal sample sizes in each arm, and a 10% increase in the 1st group led to a 5% increase in power. Conclusion: Various baseline EDSS proportions yielded different CDPRs and power, suggesting caution in interpretation of treatment effects across trials that enrolled participants with different proportions of baseline EDSS.

L-arginine effect on inflammatory mediators: A systematic review of randomized controlled clinical trials

2019 ◽  
pp. 1-9 ◽  
Author(s):  
Seyed Reza Mirhafez ◽  
Mitra Hariri
Keyword(s):  
Systematic Review ◽  
Clinical Trials ◽  
Inflammatory Mediators ◽  
Randomized Clinical Trials ◽  
Randomized Controlled Clinical Trials ◽  
Patients With Cancer ◽  
Reactive Protein ◽  
Randomized Controlled ◽  
Human Adults ◽  
Factor Α

Abstract. L-arginine is an important factor in several physiological and biochemical processes. Recently, scientists studied L-arginine effect on inflammatory mediators such as C-reactive protein (CRP), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). We conducted a systematic review on randomized controlled trials assessing L-arginine effect on inflammatory mediators. We searched data bases including Google scholar, ISI web of science, SCOPUS, and PubMed/Medline up to April 2019. Randomized clinical trials assessing the effect of L-arginine on inflammatory mediators in human adults were included. Our search retrieved eleven articles with 387 participants. Five articles were on patients with cancer and 6 articles were on adults without cancer. L-arginine was applied in enteral form in 5 articles and in oral form in 6 articles. Eight articles were on both genders, two articles were on women, and one article was on men. L-arginine could not reduce inflammatory mediators among patients with and without cancer except one article which indicated that taking L-arginine for 6 months decreased IL-6 among cardiopathic nondiabetic patients. Our results indicated that L-arginine might not be able to reduce selected inflammatory mediators, but for making a firm decision more studies are needed to be conducted with longer intervention duration, separately on male and female and with different doses of L-arginine.

Ongoing randomized clinical trials for the treatment of thrombosis in the antiphospholipid syndrome

2001 ◽  
Vol 21 (02) ◽  
pp. 77-81 ◽  
Author(s):  
G. Finazzi
Keyword(s):  
Clinical Trials ◽  
Large Scale ◽  
Low Dose ◽  
Randomized Clinical Trials ◽  
Oral Anticoagulants ◽  
Collaborative Study ◽  
Clinical Problem ◽  
Vascular Events ◽  
Dose Oral ◽  
Adverse Pregnancy

SummaryThrombotic events are a major clinical problem for patients with antiphospholipid antibodies (APA). However, current recommendations for their prevention and treatment are still based on retrospective studies. Data from large scale, prospective clinical trials are required to ultimately identify the optimal management of these patients. To date, at least four randomized studies are underway. The WAPS and PAPRE clinical trials are aimed to establish the correct duration and intensity of oral anticoagulation in APA patients with major arterial or venous thrombosis. The WARSS-APASS is a collaborative study to evaluate the efficacy and safety of aspirin or low-dose oral anticoagulants in preventing the recurrence of ischemic stroke. The recently announced UK Trial compares low-dose aspirin with or without low-intensity anticoagulation for the primary prevention of vascular events in APA-positive patients with SLE or adverse pregnancy history, but still thrombosis-free. It is hoped that the results of these trials will be available soon since clinicians urgently need more powerful data to treat their patients with the APA syndrome.

Planning the Size of Clinical Trials with Allowance for Patient Noncompliance

1990 ◽  
Vol 29 (03) ◽  
pp. 243-246 ◽  
Author(s):  
M. A. A. Moussa
Keyword(s):  
Clinical Trial ◽  
Clinical Trials ◽  
Sample Size ◽  
Event Rate ◽  
Survival Functions ◽  
Time Intervals ◽  
Patient Noncompliance ◽  
Event Rates ◽  
Larger Sample

AbstractVarious approaches are considered for adjustment of clinical trial size for patient noncompliance. Such approaches either model the effect of noncompliance through comparison of two survival distributions or two simple proportions. Models that allow for variation of noncompliance and event rates between time intervals are also considered. The approach that models the noncompliance adjustment on the basis of survival functions is conservative and hence requires larger sample size. The model to be selected for noncompliance adjustment depends upon available estimates of noncompliance and event rate patterns.

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