topic Re: GENMOD: Longitudinal linear regression with continuous dependent variable in Statistical Procedures

GENMOD: Longitudinal linear regression with continuous dependent variable

cbt2119 — Fri, 31 May 2019 03:07:35 GMT

Dear SAS Community,

I am fitting a couple of generalized linear regression model with continuous outcomes: BUA, SOS, SI. The independent predictors are both categorical and continuous and my data is in long form. I would like to use PROC GENMOD for this, but I'm not sure if my code is calling the correct type of model. Do I need to include a repeated statement for the visit variable or should the code below work?

Outcome=SOS (continuous)

Predictor=Group (dichotomous)

Time Variable=Visit (1,2,3)

proc genmod data=qus;
	class group (ref="2") / param=ref;
	class visit (ref="1") / param=ref;
	class id;
	model sos = group visit / dist=normal link=identity;
	run;

Thank you,

Cara

Re: GENMOD: Longitudinal linear regression with continuous dependent variable

ChrisNZ — Fri, 31 May 2019 03:08:15 GMT

Moved to Procedures community and altered title.

Re: GENMOD: Longitudinal linear regression with continuous dependent variable

Ksharp — Fri, 31 May 2019 14:32:45 GMT

Yes. You should consider use GEE or Mixed model,since you have visit variable(repeated measure).

Check

PROC GEE

PROC GENMOD + REPEATED statement

PROC MIXED

PROC GLIMMIX

Re: GENMOD: Longitudinal linear regression with continuous dependent variable

cbt2119 — Fri, 31 May 2019 14:42:02 GMT

Thank you. So when I add the following repeated statement, not much changes to my model output. Am I using the statement correctly?

proc genmod data=qus;
	class group (ref="2") / param=ref;
	class visit (ref="1") / param=ref;
	class id;
	model sos = group visit / dist=normal link=identity;
repeated subject=id;
	run;

Re: GENMOD: Longitudinal linear regression with continuous dependent variable

Ksharp — Fri, 31 May 2019 14:50:14 GMT

I think you should drop VISIT .

proc genmod data=qus;
	class group (ref="2") / param=ref;
	class id;
	model sos = group  / dist=normal link=identity;
repeated subject=id / within=visit;
	run;

Re: GENMOD: Longitudinal linear regression with continuous dependent variable

Ksharp — Fri, 31 May 2019 14:51:30 GMT

And better post it at STAT forum , @StatDave is there . I am not expert about statistic .

Re: GENMOD: Longitudinal linear regression with continuous dependent variable

cbt2119 — Fri, 31 May 2019 14:53:30 GMT

Okay, thank you, I will try this!