BookmarkSubscribeRSS Feed
sas_user4
Obsidian | Level 7

Hello,

I am running Cox regression and wanted to test effect modification across race (4 strata). This is the code I am using:

 

proc phreg data = ABC;
model asthmatt*asthma(0) = p_cvscore  tp_cvscore/risklimit;
tp_cvscore=p_cvscore*log(asthmatt);
test_proportionality: test p_cvscore, tp_cvscore;
run;
 
Is testing for effect modification the same for proportionality assumption? I need explanation and if my code correct or wrong, please. Assuming the test is approriate in this case, what other options to use if the test of proportionality was sig? I mean what to do, what statistical solutions should I proceed with?
Thanks,
 
1 REPLY 1
sas_user4
Obsidian | Level 7

To add, I got this error message (log says  P_CVSCORE in TEST statement test_proportionality is not a parameter in the model) when I used this code:

 

proc phreg data = ABC;
class p_cvscore race1c education salary ;
model asthmatt*asthma(0) = p_cvscore  tp_cvscore /risklimit;
tp_cvscore=p_cvscore*log(asthmatt);
test_proportionality: test p_cvscore, tp_cvscore;
run;

 

 

sas-innovate-2024.png

Join us for SAS Innovate April 16-19 at the Aria in Las Vegas. Bring the team and save big with our group pricing for a limited time only.

Pre-conference courses and tutorials are filling up fast and are always a sellout. Register today to reserve your seat.

 

Register now!

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.

Discussion stats
  • 1 reply
  • 1452 views
  • 0 likes
  • 1 in conversation