Dear Statalisters,
This may be a straightforward question with an obvious answer, but I need your help on it. I have a person-period dataset and I used stset command specifying origin and id as well as failure and exit. This gave me a specific number of failures and number of subjects at risk. I ran stcox using a variable that has missing values for a number of those subjects. I am trying obtain a selection variable so I can look at baseline characteristics of those subjects that were selected for this analysis.
Which of the variables that were generated through the stset command should I be using for this purpose?
stcox x
failure _d: failuredem == 2
analysis time _t: (age50dem-origin)
origin: time origin==1
enter on or after: time origin2==1
exit on or before: failuredem==1
id: id
Iteration 0: log likelihood = -1697.8111
Iteration 1: log likelihood = -1696.3502
Iteration 2: log likelihood = -1696.3477
Refining estimates:
Iteration 0: log likelihood = -1696.3477
Cox regression -- Breslow method for ties
No. of subjects = 2321 Number of obs = 15721
No. of failures = 270
Time at risk = 52641.86847
LR chi2(1) = 2.93
Log likelihood = -1696.3477 Prob > chi2 = 0.0871
------------------------------------------------------------------------------
_t | Haz. Ratio Std. Err. z P>|z| [95% Conf. Interval]
-------------+----------------------------------------------------------------
x| 1.247601 .159471 1.73 0.084 .9711212 1.602796
------------------------------------------------------------------------------
So, basically, I want to be able to describe the 2,321 subjects in that analysis. I did that before, but I can't remember how anymore. Thanks for any help you can provide,
Sincerely,
May
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