Controlled clinical trials
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Control Clin Trials · Dec 2004
Randomized Controlled Trial Multicenter Study Comparative Study Clinical TrialSymptom recording in a randomised clinical trial: paper diaries vs. electronic or telephone data capture.
Patients may be asked to register a symptom daily in clinical trials. A problem associated with this kind of registration is that patients do not always fill in the diary at the appropriate time. As there is evidence showing that memory is unreliable, this undermines the entire purpose of collecting daily data on paper diaries. We aimed to compare accuracy, autocorrelations of consecutive entries, and responsiveness in paper diaries (P-Diaries) with electronic diaries (E-Diaries) and telephone diaries (T-Diaries). ⋯ The results are consistent with the suggestion that data in the P-Diaries are not filled in at the appropriate time. Use of E-Diaries or T-Diaries improves quality and is recommended in future clinical trials.
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Control Clin Trials · Dec 2003
Randomized Controlled Trial Clinical TrialAn international multicenter protocol to assess the single and combined benefits of antiemetic interventions in a controlled clinical trial of a 2x2x2x2x2x2 factorial design (IMPACT).
For various diseases clinicians have to combine different drugs or interventions when a single drug or intervention does not lead to satisfactory results. However, quantifying the relative benefit of certain drugs or interventions when given alone and in combination under controlled conditions requires a complex factorial design. This paper describes such a method applied to a large multicenter trial for the prevention of postoperative nausea and vomiting (PONV), which may be of great interest for other specialties. ⋯ Eligible patients are adults scheduled for elective surgery under general anesthesia with an increased risk for PONV so that the expected incidence in the control group (with none of the six antiemetic interventions) is approximately 60%. In order to allow analyses for up to three factor interactions, a sample size was estimated to be in the range of approximately 5000 patients. To the best of our knowledge this is the first randomized controlled trial of a six-way factorial design that may serve as an example for numerous other medical specialties.
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Control Clin Trials · Oct 2003
Randomized Controlled Trial Clinical TrialLook AHEAD (Action for Health in Diabetes): design and methods for a clinical trial of weight loss for the prevention of cardiovascular disease in type 2 diabetes.
Overweight and obesity are major contributors to both type 2 diabetes and cardiovascular disease (CVD). Moreover, individuals with type 2 diabetes who are overweight or obese are at particularly high risk for CVD morbidity and mortality. Although short-term weight loss has been shown to ameliorate obesity-related metabolic abnormalities and CVD risk factors, the long-term consequences of intentional weight loss in overweight or obese individuals with type 2 diabetes have not been adequately examined. ⋯ The primary study outcome is time to incidence of a major CVD event. The study is designed to provide a 0.90 probability of detecting an 18% difference in major CVD event rates between the two groups. Other outcomes include components of CVD risk, cost and cost-effectiveness, diabetes control and complications, hospitalizations, intervention processes, and quality of life.
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Control Clin Trials · Aug 2003
Randomized Controlled Trial Clinical TrialThe Arthritis, Diet and Activity Promotion Trial (ADAPT): design, rationale, and baseline results.
Osteoarthritis (OA) of the knee leads to restrictions of physical activity and ability to perform activities of daily living. Obesity is a risk factor for knee OA and it appears to exacerbate knee pain and disability. The Arthritis, Diet, and Activity Promotion Trial (ADAPT) was developed to test the efficacy of lifestyle behavioral changes on physical function, pain, and disability in obese, sedentary older adults with knee OA. ⋯ Other measurements included timed stair climb, distance walked in 6 minutes, strength, gait, knee pain, health-related quality of life, knee radiographs, body weight, dietary intake, and cost-effectiveness of the interventions. We report baseline data stratified by level of overweight and obesity focusing on self-reported physical function and physical performance tasks. The results from ADAPT will provide approaches clinicians should recommend for behavioral therapies that effectively reduce the incidence of disability associated with knee OA.
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Control Clin Trials · Jun 2003
Randomized Controlled Trial Clinical TrialPerceptions of equipoise are crucial to trial participation: a qualitative study of men in the ProtecT study.
Recruitment to trials is known to be difficult. Previous research suggests that a crucial factor may be participants' difficulty with the concept of randomization. This study explored patients' perceptions of randomization and reasons for consent or refusal to participate in the ProtecT study (a randomized trial of surgery, radiotherapy, and monitoring for localized prostate cancer). ⋯ Belief in clinical equipoise was key to participants' consent to randomization. Ensuring patients understand and accept equipoise may thus increase their readiness to consent to participate in trials. A priority for future research is to focus on the provision and presentation of suitable and effective trial information, concentrating in particular on the neglected concept of clinical equipoise.