Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: st: RE: - svy: stcox - (Stata 11)
From
Steve Samuels <[email protected]>
To
[email protected]
Subject
Re: st: RE: - svy: stcox - (Stata 11)
Date
Sat, 20 Jul 2013 20:37:27 -0400
Use -stcurve- to estimate the survival rates; output them to new data sets.
1 & 2: Compute cumulative mortality rates from the survival rates. Then plot and summarize.
3: Expected life is the integral of the survival curve (see any survival
text, including p. 48 of
https://www.iser.essex.ac.uk/files/teaching/stephenj/ec968/pdfs/
ec968lnotesv6.pdf. Therefore, you could apply -integ- to each curve in
2. If the survival curves don't descend to zero or to a "small"
number>0, then the the computed expectation will be less than the true
expectation.
If this situation arises, you can compute a restricted mean by first
adding a fake data point with time ≥ the highest censored values and
survival equal to zero. An easier approach might be to create a hazard
model with Paul Lambert's -stpm2- command (SSC), followed by -predict-
with the restricted mean options.
Some comments on your model:
1. I don't like using "missing" as a predictive category with survey data. I think that multiple imputation is the preferred approach in this situation.
2. Are there no interactions, no calendar time influences?
Steve
[email protected]
On Jul 19, 2013, at 4:30 PM, Muhuri, Pradip (SAMHSA/CBHSQ) wrote:
Hi,
Using - svy: stcox- and then post estimation commands (for which I need your help on), my goals are to calculate the following:
(1) the baseline mortality rate (for persons who are classified in the reference category for each covariate in the model);
(2) the mortality rate for particular combination of the levels of covariates (e.g., xspd2=1, agegrp5=5 & sex=2); and
(3) model-based life expectancy for particular combination of the levels of covariates (e.g., xspd2=1, agegrp5=5 & sex=2).
The following code gives me the output that is limited to coefficient, etc.
svyset psu [pweight=wt8], strata (stratum) vce(linearized) singleunit(missing)
stset interval [pweight=wt8], failure(mortstat==1)
capture noisily: svy: stcox ib2.xspd2 i.agegrp5 i.sex ib3.x_xsmoke, nohr
Survey: Cox regression
Number of strata = 339 Number of obs = 238811
Number of PSUs = 678 Population size = 200969312
Design df = 339
F( 9, 331) = 2090.43
Prob > F = 0.0000
------------------------------------------------------------------------------
| Linearized
_t | Haz. Ratio Std. Err. t P>|t| [95% Conf. Interval]
-------------+----------------------------------------------------------------
1.xspd2 | 2.071856 .0856399 17.62 0.000 1.910069 2.247346
|
agegrp5 |
2 | 3.290646 .1558252 25.15 0.000 2.997982 3.611881
3 | 8.49614 .3434431 52.93 0.000 7.846751 9.199271
4 | 21.41636 .7986149 82.17 0.000 19.90173 23.04627
5 | 64.71143 2.359975 114.34 0.000 60.23198 69.52402
|
2.sex | .7195701 .0139644 -16.96 0.000 .6926199 .7475689
|
x_xsmoke |
1 | 2.233029 .0573213 31.30 0.000 2.123078 2.348674
2 | 1.32416 .0291701 12.75 0.000 1.268008 1.382798
9 | 1.464324 .1946862 2.87 0.004 1.127359 1.902009
------------------------------------------------------------------------------
Could anyone please help me with the Stata postestimation code and point me to the relevant references to produce results for (1), (2), and (3), as referred to above?
Thank you in advance.
Pradip
Pradip K. Muhuri, PhD
Statistician
Substance Abuse & Mental Health Services Administration
The Center for Behavioral Health Statistics and Quality
Division of Population Surveys
1 Choke Cherry Road, Room 2-1071
Rockville, MD 20857
Tel: 240-276-1070
Fax: 240-276-1260
e-mail: [email protected]
The Center for Behavioral Health Statistics and Quality your feedback. Please click on the following link to complete a brief customer survey: http://cbhsqsurvey.samhsa.gov
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/faqs/resources/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/faqs/resources/statalist-faq/
* http://www.ats.ucla.edu/stat/stata/