# st: marginals and unconditional standard errors

 From susan@hailpern.com To statalist@hsphsun2.harvard.edu Subject st: marginals and unconditional standard errors Date Sat, 08 Aug 2009 05:25:22 -0700

```Hi All,

I posted earlier about an inability to obtain predicted margins using
Stata 11.

This fails with the following error message:

. margins x, vce(unconditional)
unconditional standard errors derived assuming full estimation sample;
indepvars dropped observations from the estimation sample

As a reminder, 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.

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
------------------------------------------------------------------------------

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```