Hi all,   I am testing an interaction between two categorical variables; the first variable has 5 levels and the other has 4. However, I just want to contrast some levels of this interaction and obtain an overall p-value for those interaction terms being contrasted. Is that possible? if so how?   Any help would be appreciated. ... View more

  Class Level Information Class Value Design Variables group A 1 0           B 0 1           C 0 0 sex Female 0       Male 1   proc phreg data=sasuser.ami; class group(ref='C') sex(ref='Female') / param=ref order=internal; model days*status(0) = group sex group*sex / ties=Efron; * Contrasts among groups for SEX=Male and SEX=Female. *; contrast 'AvsB sex=Male' group 1 -1 sex 0 group*sex 1 -1 / estimate=exp e; contrast 'AvsC sex=Male' group 1 0 sex 0 group*sex 1 0 / estimate=exp e; contrast 'BvsC sex=Male' group 0 1 sex 0 group*sex 0 1 / estimate=exp e; contrast 'AvsB sex=Female' group 1 -1 sex 0 group*sex 0 0 / estimate=exp e; contrast 'AvsC sex=Female' group 1 0 sex 0 group*sex 0 0 / estimate=exp e; contrast 'BvsC sex=Female' group 0 1 sex 0 group*sex 0 0 / estimate=exp e; * Contrasts among sexes for groups A, B, and C. *; contrast 'Male vs Female group=A' group 0 0 sex 1 group*sex 1 0 / estimate=exp e; contrast 'Male vs Female group=B' group 0 0 sex 1 group*sex 0 1 / estimate=exp e; contrast 'Male vs Female group=C' group 0 0 sex 1 group*sex 0 0 / estimate=exp e; * Contrast that cannot be replicated with a HAZARDRATIO statement. This *; * contrast compares group A with the average of groups B and C for males. *; contrast 'A vs (B+C)/2 at sex=Male' group 1 -0.5 sex 0 group*sex 1 -0.5 / estimate=exp e; run; ... View more