date differences in two datasets
Hi, I have two datasets on a cohort of patients. One has dates of test “a” and the other has dates of test “b”. the number of tests a and b on a subject vary (i.e., some have a lot of a and few b or visa versa) I need to find all instances where tests a and b are within a timeframe (90 days for this project). How could I automate the comparison of all combinations of test a and b to find the te...