Pool data from two different cohorts

[hovliza]

Hello, I am performing a survival analysis with harmonized data from two different cohorts. Is there something in SAS in which I can pool the data for the two different cohorts. So give more weight to one of the cohorts compared to the other in my PHREG procedure? Thank you!

[ebowen]

If the variable names are the same, you should be able to stack the datasets and assign different weights to the two cohorts. You can then use the WEIGHT statement in PHREG to assign the weighted value to the data. Here's one way to add the weights as you stack the datasets:

data out;
	set dataset1(in=in1) dataset2(in=in2);
	if in1 then Weight=0.25;
	else if in2 then Weight=0.75;
	else Weight=0; *probably not needed;
run;

[hovliza]

Thank you, this helps a lot!