Hello,
I am having problems using the Stata 10 "margins" command with survey
data.
I have a created a subpop of ~2500 observations (total 5000+) and would
like to obtain the age- sex- race adjusted prevalence of my dichotomous
outcome by cystatin-c quartile. Data is svyset; svy logistic model
including age, sex and race and cystatin-c was run, followed by the
marginals command.
The output says (not estimable). (below)
Can anyone help? I do get estimations if I take it out of survey mode,
Thanks,
Sue
. svy, subpop(subpopnodm): logistic pad i.x age56 sex01 race2
(running logistic on estimation sample)
Survey: Logistic regression
Number of strata = 28 Number of obs =
5684
Number of PSUs = 57 Population size =
230532837
Subpop. no. of obs =
2472
Subpop. size =
90812359.8
Design df =
29
F( 6, 24) =
28.73
Prob > F =
0.0000
------------------------------------------------------------------------------
| Linearized
pad | Odds Ratio Std. Err. t P>|t| [95% Conf.
Interval]
-------------+----------------------------------------------------------------
x |
2 | 1.521746 .5364044 1.19 0.243 .7400256
3.12923
3 | 4.057542 2.135947 2.66 0.013 1.382564
11.90805
4 | 9.510348 3.931692 5.45 0.000 4.083106
22.15145
|
age56 | 4.655526 2.164545 3.31 0.003 1.798843
12.04881
sex01 | 1.14324 .236113 0.65 0.522 .749361
1.744149
race2 | 2.314983 .5035135 3.86 0.001 1.483732
3.611936
------------------------------------------------------------------------------
. margins i.x , subpop(if subpopnodm==1)
Predictive margins Number of obs =
3009
Subpop. no. obs =
2472
Model VCE : Linearized
Expression : Pr(pad), predict()
------------------------------------------------------------------------------
| Delta-method
| Margin Std. Err. z P>|z| [95% Conf.
Interval]
-------------+----------------------------------------------------------------
x |
1 | (not estimable)
2 | (not estimable)
3 | (not estimable)
4 | (not estimable)
------------------------------------------------------------------------------
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