topic Re: PROC GENMOD LSMEANS REFERENCE in SAS Procedures

PROC GENMOD LSMEANS REFERENCE

superbibi — Thu, 20 Jun 2019 14:37:30 GMT

Hi SAS users,

My current code only shows the adjust p-values with vis = 30 as the reference group. If I want to use vis = 20 as the reference group, how should I modify the code?

PROC SORT DATA = test ;
BY VIS;
RUN;

PROC GENMOD DATA = test;
CLASS VAL  SUBNUM VIS (REF = "20" )  ;
MODEL VAL =  VIS/DIST = BIN ;
REPEATED SUBJECT = SUBNUM/CORR = UNSTR CORRW;
LSMEANS VIS/PDIFF ADJUST = DUNNETT;
RUN;

Re: PROC GENMOD LSMEANS REFERENCE

FreelanceReinh — Thu, 20 Jun 2019 14:57:14 GMT

Hi @superbibi,

I think the result from

LSMEANS VIS/PDIFF=control('20') ADJUST = DUNNETT;

looks promising (cf. documentation of the PDIFF option).

Re: PROC GENMOD LSMEANS REFERENCE

superbibi — Thu, 20 Jun 2019 20:45:52 GMT

Thank you very much! It works.

Re: PROC GENMOD LSMEANS REFERENCE

superbibi — Thu, 20 Jun 2019 20:49:32 GMT

Is there a way to calculate the overall p-value for vis using proc genmod? In the attached code, I got only the p-values for each paired comparison.

Re: PROC GENMOD LSMEANS REFERENCE

FreelanceReinh — Thu, 20 Jun 2019 22:27:53 GMT

Do you mean the Wald chi-square test?

  Wald Statistics For Type 3 GEE Analysis

                          Chi-
Source           DF     Square    Pr > ChiSq

VIS               7      37.94        <.0001

To obtain this, you need to add the TYPE3 and WALD options to the MODEL statement:

MODEL VAL =  VIS/DIST = BIN type3 wald;