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?
Does your data like Contingency Table ? If it was ,check PROC FREQ + TREND option.
Or try ANOVA via PROC GLM .
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.
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.
Build your skills. Make connections. Enjoy creative freedom. Maybe change the world. Registration is now open through August 30th. Visit the SAS Hackathon homepage.
Register today!Learn the difference between classical and Bayesian statistical approaches and see a few PROC examples to perform Bayesian analysis in this video.
Find more tutorials on the SAS Users YouTube channel.