Current opinion in neurology
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Curr. Opin. Neurol. · Feb 2007
ReviewStroke and the statistics of the aspirin/clopidogrel secondary prevention trials.
Four randomized trials have investigated the combination of clopidogrel plus aspirin for secondary prevention of vascular outcomes in 54,949 patients. Here we argue that attempts to translate the results of these trials into clinical practice have proven frustrating because of the following statistical considerations: differences in study populations and study design make comparisons difficult (comparisons of 'apples and oranges'), incomplete factorial designs prevent proper contrasts (examining 'bits and pieces' of a larger picture), results concern widely different vascular diseases ('puzzling subgroups'), and negative results are easily misinterpreted. ⋯ Even after four large randomized trials we still do not know the optimal treatment for secondary prevention of stroke. We suggest that subsequent trials should focus on a particular vascular disease and test hypotheses that relate to a specific mechanism.