Articles: cross-over-studies.
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Control Clin Trials · Oct 2004
The utility of partial cross-over designs in early phase randomized prevention trials.
In this note, we outline the benefits of a partial cross-over design for a class of experiments where the interest is the cumulative effect of dose versus placebo. The goal of our design strategy is to answer several complex question efficiently in a phase II setting with a minimal number of assumptions with an eye towards planning a phase III study.
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Critical care medicine · Mar 2004
Unintended bias, clinical trial results, and the heparin post hoc crossover fallacy.
To describe the unintended pitfalls in the interpretation of postrandomization events in clinical trials. ⋯ Great caution should be exercised in the post hoc interpretation of the potential efficacy of nonrandomized treatments such as heparin therapy derived from phase III clinical data of other drugs for sepsis. The therapeutic value of heparin as a treatment modality in severe sepsis can best be determined in a formal, randomized, prospective clinical trial. This will obviate the unavoidable selection bias and allocation bias intrinsic to postrandomization events in clinical trials with a high early mortality rate such as severe sepsis and septic shock.
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Randomized Controlled Trial Comparative Study Clinical Trial
Intravenous adenosine alleviates neuropathic pain: a double blind placebo controlled crossover trial using an enriched enrolment design.
Adenosine analogs produce analgesic actions in nociceptive paradigms and alleviate manifestations of neuropathic pain in nerve injury models in rodents. In humans, previous work indicates an analgesic effect for adenosine administered intravenously in postoperative and neuropathic pain. In this double blind placebo controlled crossover trial, we used an enriched enrolment design to determine the effects of intravenous adenosine (50 microg/kg/min over 60min) on neuropathic pain. ⋯ Adenosine also led to a significant reduction in pinprick hyperalgesia, but not in allodynia. Three patients from Phase 1 of the trial experienced long term resolution of their pain following intravenous adenosine (5,16,25 months). The results of this study support previous reports that indicate intravenous adenosine alleviates neuropathic pain and hyperalgesia.
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Objective. Intrathecal opioid/local anesthetic mixtures are a popular alternative in contemporary treatment of chronic nonmalignant pain. Unfortunately, its use is based solely on retrospective studies or anecdotal reports. ⋯ Addition of bupivacaine to the intrathecal opioid failed to produce significant improvement in pain control. Conclusion. At currently used doses, intrathecal opioid bupivacaine mixtures are not more efficacious in the treatment of chronic nonmalignant pain than opioid alone.