turn on suggestions

Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.

Showing results for

Find a Community

- Home
- /
- SAS Programming
- /
- General Programming
- /
- Cox proportional hazards model with time-dependent...

Topic Options

- RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page

- Mark as New
- Bookmark
- Subscribe
- RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content

11-04-2015 08:26 AM

As part of an analysis (I can provide additional details if needed) I need to obtain the estimate of the linear predictor (i.e. the β’x part of S(t) = S0(t) ∙ exp(β’x)) for each time point for each patient from a cox proportional hazards model with time-dependent covariates. However, I cannot figure out how to do that in SAS when the model includes a time-dependent covariate. In a simple cox model, it is relatively easy to get by specifying “baseline” and “xbeta”:

**proc** **phreg** data = data;

model time*event(**0**) = variables;

baseline covariates = data xbeta = score;

**run**;

However, the “baseline” statement does not work when you introduce a time-dependent covariate. Does anyone know how I can obtain the estimates?

Much appreciated,

Lars

- Mark as New
- Bookmark
- Subscribe
- RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content

Posted in reply to Lars_Andersen

11-04-2015 10:46 AM

- Mark as New
- Bookmark
- Subscribe
- RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content

Posted in reply to BTAinVA

11-04-2015 10:54 AM

Hi Brian,

Yes, I did previously see that but it was not clear to me that it answers my questions. Do you suggest I use the "counting process" method?

Thanks,

Lars

- Mark as New
- Bookmark
- Subscribe
- RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content

Posted in reply to Lars_Andersen

11-04-2015 11:04 AM

I would try the programming statement method first as it seems much simpler and gives the same results.

- Mark as New
- Bookmark
- Subscribe
- RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content

Posted in reply to BTAinVA

11-04-2015 11:10 AM

As noted in my original post, the programming method and "baseline" statement cannot be used for models with time-dependent covariates.