topic How to get horizontal line for median in KM plot using proc lifetest for SAS 9.4 and EG 8.2 in Statistical Procedures

How to get horizontal line for median in KM plot using proc lifetest for SAS 9.4 and EG 8.2

Sairampulipati — Thu, 31 Jul 2025 13:29:23 GMT

Hi,

I am faicng issue in getting a median line horizontal at 0.5 where my Y-axis is 0 to 1 by 0.2 for Kaplan Meier Plot using proc life test. I am using SAS EG and platform is SAS 9.4;

Re: How to get horizontal line for median in KM plot using proc lifetest for SAS 9.4 and EG 8.2

FreelanceReinh — Thu, 31 Jul 2025 14:29:29 GMT

Hi @Sairampulipati,

Do you face the same issue if you try to replicate the example Adding a Y-Axis Reference Line from the SAS documentation, that is, if you compile the macro code copied from https://support.sas.com/documentation/onlinedoc/stat/ex_code/151/templft.html and then run the code from the example?

Re: How to get horizontal line for median in KM plot using proc lifetest for SAS 9.4 and EG 8.2

Sairampulipati — Thu, 31 Jul 2025 16:07:31 GMT

Hi @FreelanceReinh,

Thank you so much this works, I have few questions about the macro. Is the macro developed by SAS and is it validated? Can you please share more details about the macro. Thanks again.

Re: How to get horizontal line for median in KM plot using proc lifetest for SAS 9.4 and EG 8.2

FreelanceReinh — Thu, 31 Jul 2025 17:22:10 GMT

You're welcome.

Those macros are closely linked to the name of SAS employee Warren F. Kuhfeld, PhD (now retired), see his initials in the header of the code (where also the "update" date July 25, 2013 documents how long they have been available and certainly used by many SAS programmers around the globe). So I assume that the macros were developed by himself or under his guidance. At least, he is the author of the documentation, as you can read in https://blogs.sas.com/content/author/warrenkuhfeld/ together with more information about him. He also wrote the 2017 blog article Customizing the Kaplan-Meier Plot and answered related questions in the SAS Support Communities, e.g., Re: Format KM curve with median survival line.

I can't imagine that SAS Institute would provide such macros in their official documentation if they weren't validated.

Re: How to get horizontal line for median in KM plot using proc lifetest for SAS 9.4 and EG 8.2

WarrenKuhfeld — Fri, 01 Aug 2025 11:21:26 GMT

Yes, it was all me. I covered every example that I ever heard of at the time where a user wanted to customize the KM plot. Every example in that chapter used the actual macros.