Comments on BzST: Statistical considerations and psychological effec...

Thanks Ron -- you are suggesting improved gaming, ...

2011-09-26T05:16:39.125-07:00

Thanks Ron -- you are suggesting improved gaming, but my main concern is that "the incentives are not aligned" for the researchers, participants and physicians. Although I have never been directly involved in a clinical trial, I am wondering if there are "better aligned" solutions.

Blocks are usually defined in much smaller sizes t...

2011-09-25T22:22:23.218-07:00

Blocks are usually defined in much smaller sizes than necessary. For example, in a comparative trial with 12 patients per center, a block size of 12 would be adequate for balancing treatment versus placebo. Common practice however is to set up blocks of size 4, thus increasing the 'psychological' and uncovering risks mentioned above.

this emphasizes the importance of running a

Thanks for these comments Yossi - Indeed, the book...

2011-09-21T08:11:43.047-07:00

Thanks for these comments Yossi - Indeed, the book also discusses allocation for bioequivalence and other types of goals. I find it illuminating to see so many issues in clinical trials that are not mentioned in other contexts, yet perhaps they should!

There is also a fascinating discussion about practical hindrances to blinding, such as taste, color, or other features of the medicine

A few comments. Regarding unequal allocation – wh...

2011-09-21T02:36:53.827-07:00

A few comments.

Regarding unequal allocation – when the sample size is fixed, it is true that equal allocation usually maximizes the sample size (at least when the distribution of the test statistic under the null hypothesis is symmetric). However, if an unequal allocation is desired, it is easy to calculate the sample size that will provide the desired power.

There are many