Turn on suggestions

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

Showing results for

- Home
- /
- Analytics
- /
- Stat Procs
- /
- create a survival curve not using Lifetest but Phreg

Options

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

- Mark as New
- Bookmark
- Subscribe
- Mute
- RSS Feed
- Permalink
- Report Inappropriate Content

Posted 10-30-2011 11:20 AM
(1540 views)

Hi, I have some questions about how to create survival curve when I consider some other covariates. Although I have referred to Example 64.1 (9.2 user guide), I also face some difficulty. In the example, there are only two interested covariates which are used to divide the two groups and are the category variables. If I have more than two covariates which include even up to 10 covariates or numerical variables, it is not easy to divide groups using the covariates. How should I create the survival curves when I consider much more covariates which include numerical variables? thanks.

6 REPLIES 6

- Mark as New
- Bookmark
- Subscribe
- Mute
- RSS Feed
- Permalink
- Report Inappropriate Content

Cynthia's response #2 in http://communities.sas.com/thread/31692?tstart=0 is the way to do it unless you are going to stratify on the variables rather than model them. However, you can't stratify on a continuous variable, so you are back to fixing the level of each covariate and computing the estimate of the curve at that level. See Harrell's Regression Modeling Strategies book for more on the theory and process.

I would typically draw a curve for each of the levels of the categorical variable of interest (e.g. treatment) and set the other variables to a default value (e.g. male sex) or to a mean (e.g. for age). You can do this incorporating both stratification and modeling variables.

Doc Muhlbaier

Duke

- Mark as New
- Bookmark
- Subscribe
- Mute
- RSS Feed
- Permalink
- Report Inappropriate Content

- Mark as New
- Bookmark
- Subscribe
- Mute
- RSS Feed
- Permalink
- Report Inappropriate Content

SAS has Books By Users by both Cantor and Allison on Survival analysis; both are readable. Closer at hand for you is the SAS manual. For instance, example 66.3 in the SAS 9.3 section of the SAS/Stat manual seems to fit your situation pretty well:

SAS 9.3 has made significant enhancements to the ODS statistical graphics, which may help you on drawing the plots (I don't think that the syntax has changed materially.)

- Mark as New
- Bookmark
- Subscribe
- Mute
- RSS Feed
- Permalink
- Report Inappropriate Content

- Mark as New
- Bookmark
- Subscribe
- Mute
- RSS Feed
- Permalink
- Report Inappropriate Content

In SAS 9.3, simply specify /plots=survival. It's in the manual.

- Mark as New
- Bookmark
- Subscribe
- Mute
- RSS Feed
- Permalink
- Report Inappropriate Content

thank you a lot. I will try it according to what you said.

Build your skills. Make connections. Enjoy creative freedom. Maybe change the world. **Registration is now open through August 30th**. Visit the SAS Hackathon homepage.

What is ANOVA?

ANOVA, or Analysis Of Variance, is used to compare the averages or means of two or more populations to better understand how they differ. Watch this tutorial for more.

Find more tutorials on the SAS Users YouTube channel.