If you are using linear regression then you merely have
to specify the variance of X i.e. the doses per person
you are selecting by design.
You can use the command sampsi_reg available on SSC
just type
ssc install sampsi_reg
If you want to repeat this command many times and produce a
power graph or sample size graph install samplesize also
available on SSC
ssc install samplesize
cheers
Ade
---- Original Message ----
From: [email protected]
To: [email protected]
Subject: RE: st: Sample size calculation for dose response
Date: Mon, 13 Feb 2006 16:17:04 -0500
>
>Hello.
>
>Anyone know how to do sample size calculations for studies looking at
>dose response?
>Essentially, we want to see if levels of a biomarker (call it X)
>changes when subjects are inseminated with varying levels of semen
>(10 units, 100 units, 1000 units). The biomarker X would be a
>continuous variable. So I want to see the correlation between
>biomarker X and these 3 levels of semen.
>
>Any guidance would be helpful.
>Thanks.
>
>*
>* For searches and help try:
>* http://www.stata.com/support/faqs/res/findit.html
>* http://www.stata.com/support/statalist/faq
>* http://www.ats.ucla.edu/stat/stata/
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
