trend analysis

[docfermi]

I am trying to see whether there is a significant upward or downward trend in certain infection over time.  I calculated rates/95% confidence intervals using proc genmod.  Can I use Cochran-armitage test (year vs. mean proportion) for trends?  If not, what method would be appropriate?

[Ksharp]

Does your data like Contingency Table ? If it was ,check PROC FREQ + TREND option.

Or try ANOVA via PROC GLM .

[docfermi]

I got yearly rates with 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.

[Ksharp]

Since all your independent variables are CLASS variables, then your data indeed like a contingency table.

Check PROC FREQ + TEAND option. there is an example of it in PROC FREQ's documentation.