Contemporary clinical trials
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Contemp Clin Trials · Mar 2008
Randomized Controlled Trial Multicenter Study Comparative StudyBronchodilation of formoterol administered with budesonide: device and formulation effects.
Previous single-dose crossover studies have established therapeutic equivalence of formoterol when administered at the same nominal dose via a dry powder inhaler (DPI) or pressurized hydrofluoroalkane (HFA) metered-dose inhaler (pMDI). Demonstration of equivalent bronchodilation for formoterol administered as formoterol DPI or combined with budesonide in one pMDI (budesonide/formoterol pMDI) would indicate that the greater clinical efficacy of the budesonide/formoterol pMDI combination is due to the budesonide contribution and not to differences in formoterol formulation or delivery device. ⋯ Budesonide/formoterol pMDI affords equivalent formoterol-related bronchodilatory effects versus formoterol DPI at formoterol doses of 4.5, 9, and 18 microg, indicating that practitioners can expect and patients will experience similar bronchodilation from the same dose of formoterol whether it is delivered as monotherapy via a DPI or as combination therapy with budesonide via one pMDI.
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Contemp Clin Trials · Mar 2008
Effectiveness of recruitment in clinical trials: an analysis of methods used in a trial for irritable bowel syndrome patients.
A successful clinical trial is dependent on recruitment. Between December 2003 and February 2006, our team successfully enrolled 289 participants in a large, single-center, randomized placebo-controlled trial (RCT) studying the impact of the patient-doctor relationship and acupuncture on irritable bowel syndrome (IBS) patients. This paper reports on the effectiveness of standard recruitment methods such as physician referral, newspaper advertisements, fliers, audio and video media (radio and television commercials) as well as relatively new methods not previously extensively reported on such as internet ads, ads in mass-transit vehicles and movie theater previews. ⋯ Using a novel metric, the efficacy index, we found that physician referrals and flyers were the most effective recruitment method in our trial. Despite some methods being more efficient than others, all methods contributed to the successful recruitment. The iterative use of the efficacy index during a recruitment campaign may be helpful to calibrate and focus on the most effective recruitment methods.
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Contemp Clin Trials · Mar 2008
Who controls the placebo? Introducing a Placebo Quality Checklist for pharmacological trials.
Randomised placebo-controlled trials (RCT) are an invaluable tool for testing the efficacy of new treatment strategies. The choice of placebo in an RCT can affect not only patients' physical and psychological response to a particular intervention, but also the trial setting, the success of patient blinding to the intervention, and therefore the outcome of the study and the efficacy of treatment in general. Therefore the placebo is intrinsically tied to the trial's methodology and results. ⋯ A placebo which was not properly validated may even have specific effects that lead to false negative results. To address this deficit, we propose a measure of placebo quality using the term placebo to assess the physical aspect of a dummy treatment used in the placebo group of a randomised controlled trial (RCT). The Placebo Quality Checklist (PQC) described here may help investigators select an appropriate placebo and help both investigators and critical readers interpret the findings of studies with more care.
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Contemp Clin Trials · Mar 2008
Time-dependent effect of non-Hodgkin's lymphoma grade on disease-free survival of relapsed/refractory patients treated with high-dose chemotherapy plus autotransplantation.
Evaluation of time to event outcomes usually is examined by the Kaplan-Meier method and Cox proportional hazards models. We developed a modified statistical model based on histologic grade and other variables to describe the time-dependent outcome for autologous stem cell transplant (autotransplant) performed for non-Hodgkin's lymphoma (NHL) based on histologic grade and other variables. One hundred and fourteen relapsed or refractory NHL patients were treated using BCNU 600 mg/m2, etoposide 2400 mg/m2, and cisplatin 200 mg/m2 IV followed by autotransplant. ⋯ Cox proportional hazards model analysis showed that proportionality did not hold for lymphoma grade, indicating that the relationship between the grade and disease-free survival differed over time. By piece-wise Cox model, the relative risk for experiencing relapse or death after 1 year in patients with indolent compared with patients with aggressive NHL was 2.81 (p=0.019) with 95% confidence interval (1.19, 6.65). The time-dependent effect of lymphoma grade on disease-free survival suggests the need for early (within first year) incorporation of novel therapeutic approaches in management of patients with indolent NHL undergoing autotransplant.
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Contemp Clin Trials · Mar 2008
An optimization algorithm for designing phase I cancer clinical trials.
Numerous phase I dose finding clinical trials are conducted everyday to find the "maximum tolerated dose" (MTD) of a cancer treatment. Although various Bayesian designs for Phase I clinical trials have been proposed in the literature, the traditional 3+3 design is still widely used because of its algorithm-based simplicity in logistics for the clinical investigators to carry out in comparison with model-based Bayesian methods. ⋯ It searches for an approximately optimal design within a design space, in which the 3+3 design is included as a special case. Simulation studies show that the design recommended by this algorithm significantly outperforms the 3+3 design.