Comparison of medians

[German Cediel]

Hi everybody nd many thanks in advance.

I have performed a very simple RCT with 5 participants on each group (placebo and experimental) and I have measured a biomarker at three points during follow-up
Now I am interested in performing a median comparison between groups and also whithin groups testing for differences between baseline and the follow-up measures.
What is the the best test to use to test for these whiting groups differences and also if the change at each point is different between groups?

Thank you for your help.

Germán

[Carlo Lazzaro]

German:
see -qreg-, first.
That said, any inferential procedure with such a scant sample size should be considered as a bit of a stretch !

[Rich Goldstein]

I am not exactly sure what you want to test, but -permute- is likely to be your best bet and you should use the "enumerate" option; see

h permute

added: there are 252 distinct combinations of 10 units, w/5 per group and your p-value will be the the rank order of the p-value on your actual data set within the set of all 252 results (speaking loosely here)

you might also want to look at some community-contributed programs including -tstrest-, permtest1, permtest2 - use -search- to find and download