BookmarkSubscribeRSS Feed
louise0828
Calcite | Level 5

I have a dataset with a continuous variable specifying the cumulative dose of a drug received at time t (drug received at multiple time points), a visit day variable, and a continuous outcome variable. I am fitting a model that cubic spline model with knots at the study days the drug is received to model the outcome variable with cumulative dose and a spline for visit day as predictors (and the interaction of day with dose) with subject specific intercept and slope. Below is the model code that I've used:

 

proc glimmix data=dat;

     class subjectid;

     effect = spl(spline day/degree=3 knotmethod=list(5 10 15));

     model outcome = spl | dose;

     random intercept day / subject=subjectid;

run;

 

I would like to estimate the contrast for a subject receiving a dose of 20 and a subject receiving a dose of 10 at day 12. I tried to write the following estimate statement:

estimate "Dose 20 vs Dose 10 at Day 12" spl*dose [1, 12 20][-1, 12 10];

 

But the estimate is showing as "Non-est". Am I writing the contrast wrong? 

1 REPLY 1
louise0828
Calcite | Level 5

I have a dataset with a continuous variable specifying the cumulative dose of a drug received at time t (drug received at multiple time points), a visit day variable, and a continuous outcome variable. I am fitting a model that cubic spline model with knots at the study days the drug is received to model the outcome variable with cumulative dose and a spline for visit day as predictors (and the interaction of day with dose) with subject specific intercept and slope. Below is the model code that I've used:

 

proc glimmix data=dat;

     class subjectid;

     effect = spl(spline day/degree=3 knotmethod=list(5 10 15));

     model outcome = spl | dose;

     random intercept day / subject=subjectid;

run;

 

I would like to estimate the contrast for a subject receiving a dose of 20 and a subject receiving a dose of 10 at day 12. I tried to write the following estimate statement:

estimate "Dose 20 vs Dose 10 at Day 12" spl*dose [1, 12 20][-1, 12 10];

 

But the estimate is showing as "Non-est". Am I writing the contrast wrong? 

 

sas-innovate-white.png

Our biggest data and AI event of the year.

Don’t miss the livestream kicking off May 7. It’s free. It’s easy. And it’s the best seat in the house.

Join us virtually with our complimentary SAS Innovate Digital Pass. Watch live or on-demand in multiple languages, with translations available to help you get the most out of every session.

 

Register now!

What is Bayesian Analysis?

Learn the difference between classical and Bayesian statistical approaches and see a few PROC examples to perform Bayesian analysis in this video.

Find more tutorials on the SAS Users YouTube channel.

SAS Training: Just a Click Away

 Ready to level-up your skills? Choose your own adventure.

Browse our catalog!

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