sas code for trend analysis for rate (incidence)

[docfermi]

I got yearly rates with sas code below:

proc genmod data=cdi;

 class year sex age_group / param=glm;

model cdiff= year sex age_group / type3 dist=poisson link=log offset=log_discharge;

estimate "rate: year=2003" intercept 1 year 1 0 0 0 0 /e

.........;run;

I would appreciate sas codes (or references) for trend analyses.  Using Cochran armitage test would be appropriate (I am familiar with this).  

[pau13rown]

the cochran armitage trend test is from proc freq, as follows:

ods output trendtest=trendtest ;
proc freq data=cdi;
  tables cdiff*year/ trend measures cl;
run;

[lijiaqi]

I am doing similar analyses, and have same question. Could you tell me the method if you solved this problem?