Thanks - yes, I need it for each age, unfortunately. But I think we've solved it. I appreciate your time and input. ... View more

Wonderful! I needed the intck function, and didn't know it. Thanks for setting up for me so nicely. ... View more

Person years (PY) at age X = time patient spent in study in years at a particular age point (age 1 year, age 2 years, etc.)   id dob first_dt last_dt 1 05MAR1980 01JAN2005 31DEC2014 (alive throughout study) 2 12AUG2006 12AUG2006 31DEC2014 (born during study) 3 19SEP1975 01JAN2005 20MAY2011 (died or censored during study) Case ID 1 Total of 10 PY in study. 24.83 years of age at first_dt.  Desired output: .17 PY at age 24 1.00 PY at age 25 1.00 PY at age 26 1.00 PY at age 27 1.00 PY at age 28 1.00 PY at age 29 1.00 PY at age 30 1.00 PY at age 31 1.00 PY at age 32 1.00 PY at age 33 .83 PY at age 34   Case ID 2 was 0 at first_dt (her birth date). She spent 1.00 PY at age 0, 1.00 PY at age 1, 1.00 PY at age 2, 1.00 PY at age 3, 1.00 PY at age 4, 1.00 PY at age 5, 1.00 PY at age 6, 1.00 PY at age 7, and .39 PY at age 8. Total of 8.39 PY in study.   Case ID 3 was 29 at age of first_dt. She spent .71 PY at age 29, 1.00 PY at age 30, 1.00 PY at age 31, 1.00 PY at age 32, 1.00 PY at age 33, 1.00 PY at age 33, .67 PY at age 34. Total of 6.38 PY.   Does that clarify? ... View more

Expected output would be total_cohort_person_years_age_0= XX.X years total_cohort_person_years_age_1 = XX.X years total_cohort_person_years_age_2 = XX.X years etc, to age 99     This can be done on a per row/case basis and then I can sum using proc sql, but I'm thinking there may be a simpler way to do this, as I said.     First date of study was 1/1/2005, but it shouldn't matter since I have entry(first_dt) in cohort and exit from(last_dt) cohort for each person.  ... View more