Clinical trials : journal of the Society for Clinical Trials
-
It is highly desirable to terminate a clinical trial early if the emerging data suggests that the experimental treatment is ineffective, or substantially less effective than the level the study was designed to detect. Many studies have used a conditional power calculation as the basis for termination for futility. However, in order to compute conditional power one must posit an assumption about the distribution of the future data yet to be observed, such as that the original design assumptions will apply, or that the future data will have the same treatment effect as that estimated from the current 'trend' in the data. Each such assumption will yield a different conditional power value. ⋯ These methods allow the design of clinical trials that have specified operating characteristics with a pre-specified futility analysis based only on the interim quantities that have been observed. Examples are presented.
-
Benign prostatic hyperplasia (BPH), a common condition among older men, confers its morbidity through potentially bothersome lower urinary tract symptoms. Treatments for BPH include drugs such as alpha-adrenergic receptor blockers and 5-alpha reductase inhibitors, minimally invasive therapies that use heat to damage or destroy prostate tissue, and surgery including transurethral resection of the prostate. Complementary and alternative medicines are gaining popularity in the US. Two phytotherapies commonly used for BPH are extracts of the fruit of Serenoa repens, the Saw palmetto dwarf palm that grows in the Southeastern US, and extracts of the bark of Pygeum africanum, the African plum tree. ⋯ Trial design occurs in an environment of continually evolving information. In this case, emerging results from another trial suggested that a study of long-term efficacy was premature, and that an effective dose and preparation of S. repens had to be established before proceeding to a long-term clinical trial.
-
Nonadherence, inadequate monitoring, and side-effects result in suboptimal outcomes in ulcerative colitis (UC). We hypothesize that telemanagement for UC will improve symptoms, quality of life, adherence, and decrease costs. ⋯ To the best of our knowledge, our trial will be the first randomized controlled trial to evaluate telemedicine in subjects with gastrointestinal disease. We describe several issues encountered in design and implementation of our trial that will aid investigators when planning telemedicine trials in inflammatory bowel disease.