Date:         Wed, 7 Sep 2005 11:52:16 -0700
Reply-To:     sailorgirl05 <sailorgirl05@YAHOO.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         sailorgirl05 <sailorgirl05@YAHOO.COM>
Organization: http://groups.google.com
Subject:      Geometric mean rise (GMR) and confidence intervals
Comments: To: sas-l@uga.edu
Content-Type: text/plain; charset="iso-8859-1"

Hi, I hope someone can help me!
I have clinical trial data, two study groups given a booster injection
at different ages.  I want to compare antibody levels of the two groups
pre- and post-immunization.  I can get the mean GMT and 95%CI for each
group, but am trying now to calculate GMR with 95% CI for each group.
I think I have the GMR, but how to I calculate the confidence interval
for a mean ratio?
Thanks in advance!