Contemporary clinical trials
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Contemp Clin Trials · Nov 2015
Two-group time-to-event continual reassessment method using likelihood estimation.
The presence of patient heterogeneity in dose finding studies is inherent (i.e. groups with different maximum tolerated doses). When this type of heterogeneity is not accounted for in the trial design, subjects may be exposed to toxic or suboptimal doses. Options to handle patient heterogeneity include conducting separate trials or splitting the trial into arms. ⋯ Extending current dose finding designs to handle patient heterogeneity maximizes the utility of existing methods within a single trial. We propose a modification to the time-to-event continual reassessment method to accommodate two groups using a two-parameter model and maximum likelihood estimation. The operating characteristics of the design are investigated through simulations under different scenarios including the scenario where one conducts two separate trials, one for each group, using the one-sample time-to-event continual reassessment method.
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Contemp Clin Trials · Nov 2015
Randomized Controlled TrialLong-term Exercise After Pulmonary Rehabilitation (LEAP): Design and rationale of a randomized controlled trial of Tai Chi.
Persons with chronic obstructive pulmonary disease (COPD) have reduced exercise capacity and levels of physical activity. Supervised, facility-based pulmonary rehabilitation programs improve exercise capacity and reduce dyspnea, but novel long-term strategies are needed to maintain the benefits gained. Mind-body modalities such as Tai Chi which combine aerobic activity, coordination of breathing, and cognitive techniques that alleviate the physical inactivity, dyspnea, and anxiety and depression that are the hallmarks of COPD are promising strategies. ⋯ The Long-term Exercise After Pulmonary Rehabilitation (LEAP) study is a novel and clinically relevant trial. We will enroll a well-characterized cohort of persons with COPD and will comprehensively assess physiological and psychosocial outcomes. Results of this study will provide the evidence base for persons with COPD to engage in Tai Chi as a low-cost, long-term modality to sustain physical activity in persons who have completed a standard short-term pulmonary rehabilitation program.
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Contemp Clin Trials · Nov 2015
Randomized Controlled TrialThe rationale, design, and baseline characteristics of PREVENT-DM: A community-based comparative effectiveness trial of lifestyle intervention and metformin among Latinas with prediabetes.
Promotora Effectiveness Versus Metformin Trial (PREVENT-DM) is a randomized comparative effectiveness trial of a lifestyle intervention based on the Diabetes Prevention Program delivered by community health workers (or promotoras), metformin, and standard care. Eligibility criteria are Hispanic ethnicity, female sex, age ≥ 20 years, fluent Spanish-speaking status, BMI ≥ 23 kg/m(2), and prediabetes. We enrolled 92 participants and randomized them to one of the following three groups: standard care, DPP-based lifestyle intervention, or metformin. ⋯ The PREVENT-DM study successfully recruited and randomized an understudied population of Latinas with prediabetes. This trial will be the first U. S. study to test the comparative effectiveness of metformin and lifestyle intervention versus standard care among prediabetic adults in a "real-world" setting.
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Contemp Clin Trials · Nov 2015
Randomized Controlled TrialLumbar Imaging With Reporting Of Epidemiology (LIRE)--Protocol for a pragmatic cluster randomized trial.
Diagnostic imaging is often the first step in evaluating patients with back pain and likely functions as a "gateway" to a subsequent cascade of interventions. However, lumbar spine imaging frequently reveals incidental findings among normal, pain-free individuals suggesting that treatment of these "abnormalities" may not be warranted. Our prior work suggested that inserting the prevalence of imaging findings in patients without back pain into spine imaging reports may reduce subsequent interventions. We are now conducting a pragmatic cluster randomized clinical trial to test the hypothesis that inserting this prevalence data into lumbar spine imaging reports for studies ordered by primary care providers will reduce subsequent spine-related interventions. ⋯ If our study shows that adding prevalence data to spine imaging reports decreases subsequent back-related RVUs, this intervention could be easily generalized and applied to other kinds of testing, as well as other conditions where incidental findings may be common. Our study also serves as a model for cluster randomized trials that are minimal risk and highly pragmatic.
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Contemp Clin Trials · Nov 2015
ReviewA decade of individual participant data meta-analyses: A review of current practice.
Individual participant data (IPD) systematic reviews and meta-analyses are often considered to be the gold standard for meta-analysis. In the ten years since the first review into the methodology and reporting practice of IPD reviews was published much has changed in the field. This paper investigates current reporting and statistical practice in IPD systematic reviews. ⋯ While the last ten years have seen substantial changes in how IPD meta-analyses are performed there remains considerable scope for improving the quality of reporting for both the process of IPD systematic reviews, and the statistical methods employed in them. It is to be hoped that the publication of the PRISMA-IPD guidelines specific to IPD reviews will improve reporting in this area.