Statalist


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

st: Intraclass correlation and binary hierarchical models


From   "Levy, Douglas E., Ph.D." <DLEVY3@PARTNERS.ORG>
To   <statalist@hsphsun2.harvard.edu>
Subject   st: Intraclass correlation and binary hierarchical models
Date   Wed, 11 Nov 2009 15:07:28 -0500

Hi All,

This is partly a stats question, partly a Stata question. I have binary outcome
data and I'm interested in calculating intraclass correlation for a
multilevel/hierarchical model that is nested as follows: patients within
hospitals within regions. I want to know what proportion of the variance in
outcomes resides at each level of hierarchy to help direct quality control
efforts.

If my data were linear, I could run:
xtmixed Y || region: || hospital:, variance
I would add up the region, hospital, and residual variances, and see what
fraction of the total variance resided at each level.

If I had binary data and only had two levels of hierarchy, say hospital and
patient, I could run xtlogit:
xtlogit Y, re i(hospital)
and the rho statistic would be my estimate of intraclass correlation (am I
correct here?).

The "correct" model to run with my binary outcome data would be:
xtmelogit Y || region: || hospital:, variance
but this only reports the variance for region and hospital. There is no residual
variance reported to estimate the total variance (which I suppose makes sense
with binary data), and Stata does not report a level-specific rho as it does
with xtlogit.

I'd be grateful for the group's thoughts on how to tackle this issue
statistically and/or with respect to Stata.

Best,
Doug

[My apologies if this has appeared as a repost. I have tried to post this
message several times but I have not seen appear on the list.] 


The information in this e-mail is intended only for the person to whom it is
addressed. If you believe this e-mail was sent to you in error and the e-mail
contains patient information, please contact the Partners Compliance HelpLine at
http://www.partners.org/complianceline . If the e-mail was sent to you in error
but does not contain patient information, please contact the sender and properly
dispose of the e-mail.


*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/



© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index