Journal of comparative effectiveness research
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Clinical trials have largely focused on whether an intervention can work. To ensure valid and powerful testing of this hypothesis, trials attempt to maximize the effect of the intervention of interest, controlling other factors that can confound comparisons. ⋯ Minimizing biases in this pragmatic context remains a very difficult task, however. This paper reviews some of these challenges and highlights specific aspects of design that must be approached with a pragmatic attitude.
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Intravenous thrombolysis with alteplase is one of the few evidence-based acute ischemic stroke treatments. Efficacy is time dependent and not all patients treated within the 4.5 h license derive benefit. ⋯ In the Phase II study by Parsons and colleagues, tenecteplase was superior to alteplase across imaging and safety outcomes for patients selected using specific imaging criteria. We review the evidence for thrombolysis, experience with tenecteplase and compare this study with others that have used similar designs for the investigation of novel stroke lytic agents.