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

# Re: st: Re: Re: Estimating a model where the dependent variale is a ratio - Folllow up

 From Johannes Schoder To statalist@hsphsun2.harvard.edu Subject Re: st: Re: Re: Estimating a model where the dependent variale is a ratio - Folllow up Date Fri, 04 Sep 2009 14:28:53 -0400

```Thanks Martin,
Thanks Joseph,
Thanks Carlo,  your comments helped a lot!!

Just two things:
A.
Concerning Josephs reply:
I tried the following for one year (e.g. year 2000):

glm A C, i (count) family (binomial B)
and I get the result my supervisor wanted me to get.
However, why are you suggesting xtgee?
I assume that you meant that I perform my estimation for several years.
I might try that later, too.

B.
Concerning Carlos comment:
```
You think I should rather estimate a proportional hazard model (e.g. stcox or streg)? I mean you are right, I have data for each individual about its survival time, county of residence, county where it was diagnosed, age at diagnoses, etc... However I would like to see if in high volume counties (that are: counties where a lot of same cancer types i where detected) people (suffering from this cancer type i) survive longer.
```So I think I have to group the data in the following way:
```
I have to calculate for each county the average survival time of individuals diagnosed with cancer type i
```Or is this not necessary and I am loosing important information?

Again thanks a lot for your comments!
Best,
Johannes

Joseph Coveney schrieb:
```
```I wrote:

>From the SAS code that you've shown, your major professor seems to be fitting a
```
linear model.
```--------------------------------------------------------------------------------

I mistook, if I remember correctly now.  The PROC GENMOD syntax (MODEL A / B =
C;) that you showed *is* for a logistic model for which the corresponding Stata
command is (as was shown):

xtgee A C, i(country) family(binomial B)

Joseph Coveney

*
*   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/
```
```
*
*   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 1996–2015 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index