Hi all,
I am running a multivariate PROC MIXED model with a combination of continuous, categorical, and spline variables (syntax below). I have observed a significant interaction between fobss_total_personmean (continuous) and TransitionRelat (categorical, 0/1). I have attempted to probe this and test significance of the simple slopes using PROC PLM, but the direction of the slopes in the table clearly don't match; one slope is positive and one is negative in the table whereas in the figure, both are clearly positive. What am I doing wrong?
PROC MIXED data=work.import covtest noclprint method = ML; class fab400_id partner(ref="Yes") TransitionSingle(ref="Continuance of Singlehood OR In a Relationship") TransitionRelat(ref="Continuance of Relationship OR Being Single") GID_Male(ref="Gender2") dem06_L2(ref="Gender2"); model pss_sum = Age_T1 GID_male dem06_L2 visit partner Length2 TransitionSingle TransitionRelat Time mspss_total_personmean fobss_total_personmean partner*fobss_total_personmean Length2*fobss_total_personmean TransitionSingle*fobss_total_personmean TransitionRelat*fobss_total_personmean Time*fobss_total_personmean /solution; random intercept visit / sub=fab400_id type=vc; Repeated / Subject=fab400_id; store pred1; run; proc plm restore=pred1; estimate 'FOBS slope, Transition Relat 0' fobss_total_personmean 1 TransitionRelat*fobss_total_personmean 1 0, 'FOBS slope, Transition Relat 1' fobss_total_personmean 1 TransitionRelat*fobss_total_personmean 0 1 / e; effectplot slicefit (x=fobss_total_personmean sliceby=TransitionRelat=0 1); run;
I do not see your ESTIMATE statements in PROC MIXED. Please include that in your program.
Thanks,
Jill
Actually I see the E option output that might represents the coefficients used in your ESTIMATE statements.
The estimates are not the same as what PROC PLM plots. The effects in the E option output table are cut off due to long names so it is not easy to understand the effects, but it seems to me that some average of some effects are computed, which is not the case for the PROC PLM slicefit plot.
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