>> I believe you are omitting the fact that in the interim analysis the p value will be heavily influenced by the 180 or so patients who are much earlier in their course where the curve separation is much less. The time points of these alive patients would be censored but still contribute detrimentally I believe to the p value evaluation. <<
I did omit that from consideration because I assumed , probably incorrectly , that any such effect would be minimal after 180 deaths.
I agree that modeling can lead you astray when assumptions start to pile up. I would make the fewest and simplest assumptions -- that the population of 02B will look like 01/02A , that early vs. late enrollee relative health will not be a factor ( if it is , it would seem to be in favor of Provenge ) , and that the true HR is 1.5 , as by log-rank in the integrated set. I should have looked at the alternate Cox models , which I believe were in the AC docs , which could provide a sort of " average fudge-factor " that could be applied to the log-rank to arrive at an expected Cox result , though I don't recall if they looked at just 01 or both trials.
No worries , though. Clark will sort this all out for us soon. :)
Thanks to all for the input.
AI
