Date:         Fri, 19 Sep 2003 16:20:15 -0500
Reply-To:     Paul R Swank <Paul.R.Swank@uth.tmc.edu>
Sender:       "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>
From:         Paul R Swank <Paul.R.Swank@uth.tmc.edu>
Subject:      Re: repeated measures multiple comparisons
Comments: To: Paul Mcgeoghan <Mcgeoghan@Cardiff.ac.uk>
In-Reply-To:  <sf6b67e1.005@MAINCF1P.cf.ac.uk>
Content-Type: text/plain; charset="us-ascii"

Include hospital type as an independent variable (fixed effect) along
with group.

Paul R. Swank, Ph.D.
Professor, Developmental Pediatrics
Medical School
UT Health Science Center at Houston



-----Original Message-----
From: SPSSX(r) Discussion [mailto:SPSSX-L@LISTSERV.UGA.EDU] On Behalf Of
Paul Mcgeoghan
Sent: Friday, September 19, 2003 1:33 PM
To: SPSSX-L@LISTSERV.UGA.EDU
Subject: repeated measures multiple comparisons


Hi,

I have a customer who has measured Blood-glucose levels over 3 visits
while Fasting and after eating. Therefore, there are 2 measures named
Fasting and PostPar measured at 3 levels. There are 2 between subject
factors named Hospital (2 groups, private and
government) and Patient Group (control and study).

Within each hospital type, I can work out if there is a difference from
visit 1 to visit 2, visit 2 to visit 3 for the control group and the
study group seperately via the repeated measures syntax:  /EMMEANS =
TABLES(hospital*group*visit) compare(visit)

The customer would like for each hospital to compare the study group and
the control group on the mean difference from visit 1 to visit 2 and
visit 2 to visit 3 to see which group has had the biggest increase or
decrease from visit to visit.

The only way in repeated measures I can see of doing this is to Split
the file first by Hospital Type, enter the Patient Group as a Between
Subject factor and choose Repeated Contrasts. Then the Test of
Within-Subject Contrasts gives me the interaction between VISIT*GROUP
comparing Level 1 to Level 2 and Level 2 to Level 3.

Is there another way in repeated measures of achieving this?

Thanks in advance,
Paul




==================
Paul McGeoghan,
Application support specialist (Statistics and Databases), Information
Services, Cardiff University. Tel. 02920 (875035).