Dear Nicola,
Many thanks for these solutions. I confirm that both work with the larger
dataset I use.
Geoff. L.
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Nicola Orsini
Sent: 09 May 2009 14:02
To: [email protected]
Subject: st: Re: Variable estimates from GLST metaregression of
observational studies
Dear Geoff,
thanks for explaining the problem.
The problem is not related to the selection of observations to be
included in the analysis (`touse' and `if' work as intended).
The problem is to keep the actual order of the selected observations
within each study when pooling multiple studies. I modified one line
of the -glst- command to address this point.
I will post a revised ado file on both SSC and SJ archives.
In the meantime, -sort- the dataset before running -glst- command with
multiple studies
or as alternative use the option tstage() which is not affected by -
sort-.
* Solution 1
sort study_id , stable
glst ln_rr_m dosage if collecc==1, ///
se(se_glst) cov(person_y case) pfirst(study_id study_e)
* Solution 2
glst ln_rr_m dosage if collecc==1, ///
se(se_glst) cov(person_y case) pfirst(study_id study_e) ts(f)
Nicola
On May 7, 2009, at 5:19 PM, G Livesey wrote:
>
> Dear Nicola and Statalisters,
>
> I am getting different estimates each time I run a glst command on
> the same
> dataset in Stata and would be glad of suggestions of how to resolve
> the
> problem.
>
> The glst command is used here to estimate the dose-dependency of
> effect in
> observational or relative risk data.
>
> The command and syntax, and extract from a dataset in use are shown
> below.
>
> I am using Stata v9.2, an up-to-date version of glst and the log data
> (ln_rr_m and corresponding errors se_glst) were obtained with gen
> double.
>
> I would very much appreciate help with this crucial problem.
>
> With thanks,
> Geoff. Livesey
>
>
> COMMAND AND SYNTAX:
> glst ln_rr_m dosage if collect_c==1, se(se_glst) cov(person_y case)
> pfirst(study_id studyexpression) random
>
>
> DATA:
> ln_rr_m dosage collec~c se_glst person_y case study_id study_e
> 0 0 1 0 39637 281 3 2
> -.0725707 1.330824 1 .09000712 40218 265 3 2
> -.1278334 2.439844 1 .09273151 40621 241 3 2
> -.2613648 4.103374 1 .09935509 40956 198 3 2
> -.4462871 7.430433 1 .10182739 41222 156 3 2
>
> 0 0 1 0 145258 219 7 2
> -.1625189 1.212121 1 .10710753 141933 162 7 2
> -.1392621 2.203856 1 .11429413 139945 151 7 2
> -.198451 3.636364 1 .11990109 146011 132 7 2
> -.4462871 7.493112 1 .14876455 143153 77 7 2
>
> 0 0 1 0 34750 204 8 2
> -.1508229 2.187076 1 .10585496 35154 164 8 2
> -.0618754 3.827383 1 .10787362 35196 172 8 2
> -.1625189 5.649946 1 .11324987 35488 156 8 2
> -.328504 9.112817 1 .12940233 35529 148 8 2
>
> 0 0 1 0 23988 456 9 2
> -.0943106 1.14482 1 .07583086 25050 381 9 2
> -.1165338 2.289639 1 .08001615 24227 357 9 2
> -.1863296 3.663423 1 .03711996 26115 386 9 2
>
>
>
>
>
>
>
>
*
* 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/
