Trends over time

[EMB]

Hello,

I am posting my question again with some additional information.

I wish to study trends in age over time in a study including incident cases of a specific disease. Data were collected during 4 short periods 2 years apart. Each period included different participants (>1000 each).  As part of the descriptive analysis I would like to look at trends over time in age of the diagnosed individuals and show p for linear trend.

Would the following be correct for the evaluation of linear trend in age of diagnosed individuals? Any other suggestion?

proc glm;
class (time period);
model AGE=(time period);
contrast 'linear' (time period) -3 -1 1 3;
run;

Thanks!

[pau13rown]

the cochran armitage trend test is a neat one you could likely use: https://support.sas.com/documentation/cdl/en/statug/63347/HTML/default/viewer.htm#statug_freq_sect03...