Regression models with restricted cubic splines

[BayzidurRahman]

I need to fit a poisson model with offset including restricted cubic spline of a continuous covariate. I want to use the effect statement to automatically generate the spline variables at my preferred values. Can you please let me know what procedures can do it? I can see that proc genmod doesn’t allow select statement.

[sbxkoenk]

Splines are available in many procedures when you use the EFFECT statement.

The following procedures provide an EFFECT statement: GEE, GENMOD, GLIMMIX, GLMSELECT, HPMIXED, LOGISTIC, ORTHOREG, PHREG, PLM, PLS, PROBIT, QUANTLIFE, QUANTREG, QUANTSELECT, ROBUSTREG, SURVEYLOGISTIC, and SURVEYREG.

GENMOD is in the list!

Go to the Google search-bar and submit :

effect statement spline site:https://blogs.sas.com/content/iml

BR, Koen

[sbxkoenk]

Also, the TRANSREG procedure in SAS/STAT supports spline effects but has its own syntax.

You can enrich your dataset with new covariates (spline effects) using PROC TRANSREG and subsequently use the procedure of your choice.

Koen

[Rick_SAS]

> You can enrich your dataset with new covariates (spline effects) using PROC TRANSREG and subsequently use the procedure of your choice.

An easier choice is PROC GLMSELECT, which supports an OUTDESIGN= option. See the example at https://blogs.sas.com/content/iml/2019/10/16/visualize-regression-splines.html

[Rick_SAS]

I don't know where that sentence came from, but it is not correct. GENMOD does not support the EFFECT statement so the OP must use GLMMIX.

DOC for EFFECT stmt: SAS Help Center: EFFECT Statement says "This section applies to the following procedures: GLIMMIX, GLMSELECT, HPMIXED, LOGISTIC, ORTHOREG, PHREG, PLS, QUANTLIFE, QUANTREG, QUANTSELECT, ROBUSTREG, SURVEYLOGISTIC, and SURVEYREG."

[sbxkoenk]

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@Rick_SAS wrote:

I don't know where that sentence came from, but it is not correct. GENMOD does not support the EFFECT statement so the OP must use GLIMMIX.

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Oh. 🤐
That sentence came from SAS/STAT® 15.2 User's Guide.
Statistical Graphics Using ODS
The EFFECT and EFFECTPLOT Statements
SAS Help Center: The EFFECT and EFFECTPLOT Statements

Koen

[Rick_SAS]

Thanks. I have alerted the manager for that documentation. For the record, the GEE and GENMOD procedures support the EFFECTPLOT statement, but not the EFFECT statement.

[jiltao]

Use PROC GLIMMIX with the EFFECT statement.