BookmarkSubscribeRSS Feed
TomHsiung
Quartz | Level 8

Hi, everyone

 

I just learned how to process time-varying data in PROC PHREG but I only know how to do so for a data set that has only one time-varying variable. I wonder if is it possible to do the time-dependent Cox regression with two, three, or more independent cofactors (i.e., observations received several different exposures at different times). Thanks.

1 REPLY 1
TomHsiung
Quartz | Level 8

I have read parts of this paper (https://pubmed.ncbi.nlm.nih.gov/35924051/). In the statistical method section, it described,

 

Daily medication exposure and processes of care (sedative, acid inhibitors, blood transfusion, mandatory ventilation, and head-of-bed elevation, gastrointestinal decompression, and rehabilitation exercise) and medications (sedatives, opioids, neuromuscular blockers, immunosuppressive agent, neuroleptic agents, antibiotics, expectorants, vasopressors, intestinal probiotics, and neuroleptic agents) were defined as time-varying variables. Time-varying variables were measured as daily exposure from initiation of MV to the event of interested for the model of VAEs and each day from ICU admission to ICU discharge for the model of ICU discharge and ICU mortality.

 

It looks like the authors included a dozen time-varying cofactors in their Cox regression model. So, I wonder how they handled the dataset. Each patient could have a dozen time-varying cofactors, and each such cofactor could have several different values. To record the data into a dataset must be a tough mission but I don't know how they did it.

sas-innovate-2024.png

 

Time is running out to save with the early bird rate. Register by Friday, March 1 for just $695 - $100 off the standard rate.

 

Check out the agenda and get ready for a jam-packed event featuring workshops, super demos, breakout sessions, roundtables, inspiring keynotes and incredible networking events. 

 

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
  • 473 views
  • 0 likes
  • 1 in conversation