Bootstrap statistics of ECASS II data: just another post hoc analysis of a negative stroke trial?
The results of the Second European-Australasian Acute Stroke Study (ECASS II) were negative with respect to the primary endpoint. This post hoc analysis of ECASS II data was designed to make the least number of a priori assumptions. This is accomplished by a bootstrap-based hypothesis test on a non-parametric test statistic. No assumptions are made on shape or variance of population distributions and the method does not suffer from the disadvantages of dichotomization. By reducing the number of a priori assumptions, the possibilities to modify the test result by adjusting the test procedure are minimized.


RESULTS
If rt-PA does not improve the outcome (null hypothesis), the probability of observing a difference of modified ranking scale equal or larger than the one observed in ECASS II is 0.047. We therefore rejected the null hypothesis.
Stingele
R
R
Department of Neurology, University of Heidelberg, Germany. j62@ix.urz.uni-heidelberg.de
Bluhmki
E
E
Hacke
W
W
D018849:Controlled Clinical Trials as Topic; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D006801:Humans; D012107:Research Design; D013223:Statistics as Topic; D020521:Stroke / Q000188:drug therapy*; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use*
D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator