topic Proc lifetest in Statistical Procedures

Proc lifetest

Natacha — Fri, 17 Mar 2017 13:07:30 GMT

I have a pretty basic problem, but I am a new user of SAS, and I am stuck.

I am applying proc lifetest to produce graphs. My problem is that the plots produces lines with circles. I can not find any describtions, informing me about what these circles illustrates, not can I figure out a command to remove them from my graph.

I am using SAS version 9.4.

Hope anyone has some input. Thanks 🙂

Re: Proc lifetest

Reeza — Fri, 17 Mar 2017 13:20:23 GMT

Post your code and a copy of the image please.

Re: Proc lifetest

Natacha — Fri, 17 Mar 2017 13:32:19 GMT

Hi
I cannot copy my exact code or output as I am not allowed to do so.
But this is how I coded it:
proc lifetest data=X plots=(s, lls) notable; time
timevariable*outcomevariable (0); strata exposurevariable;

My outcome looks like this:

[image: Billede indsat i tekst 1]

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Re: Proc lifetest

Rick_SAS — Fri, 17 Mar 2017 13:33:07 GMT

I assume you are seeing graphs like in this documentation example:

http://support.sas.com/documentation/cdl/en/statug/68162/HTML/default/viewer.htm#statug_lifetest_examples01.htm

If you are referring to the plots, the "circles" are markers that indicate the observations in your data set. The lines are drawn to show trends and relationships.

You can use ODS OUTPUT to save the data that underlies a graph and then use PROC SGPLOT to create a new graph. The technique is described in the article "How to get data values out of ODS graphics":

ods output NegLogSurvivalPlot=SurvPlot;
proc lifetest data=Exposed plots=(survival(atrisk) logsurv);
   time Days*Status(0);
   strata Treatment;
run;

proc sgplot data=SurvPlot;
series x=Time y=__Log_Survival__ / group=Stratum;
run;

Re: Proc lifetest

Natacha — Fri, 17 Mar 2017 14:04:21 GMT

It worked! Thanks for the fast answer Rick 🙂