Bookmark and Share

Notice: On March 31, it was announced that Statalist is moving from an email list to a forum. The old list will shut down on April 23, and its replacement, statalist.org is already up and running.


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

st: marginsplot and transformed dependent variable


From   "Tom Robinson" <tomrobnz@gmail.com>
To   <statalist@hsphsun2.harvard.edu>
Subject   st: marginsplot and transformed dependent variable
Date   Thu, 25 Apr 2013 17:11:17 +1200

Hi, I am wanting to look at the effect of body mass index on CV risk
factors (HbA1c, BP, lipids) in people with T2 diabetes.

I am using linear regression to control for demographic variables and
have categorized BMI. I would like to use margins and marginsplot to
present the results.

Mt problem is that the models that include the dependent variables (the CV
risk factors) untransformed have poor post-estimation diagnostics i.e.
non-normal residuals, heteroskedasticity, and poor fit

If I transform the dependent variables (log or inverse) the models are much
better.  But then it is difficult to present the results to a general
readership.  Is it possible to take the transformed margins estimates and
un-transform them?  When I do it by hand they don't look right so maybe
this doesn't make sense.

Thanks for any advice

Tom

Tom Robinson
4 Domain St.
Devonport
ph. 445 2056
mob. 021 482 391
email. tomrobnz@gmail.com


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


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