How to calculate person years in Cox regression?

[nwang5]

Hi all,

I hope you are doing well. I am trying to calculate person years. I am not sure if there is any code we can use in proc phreg to get person year and number of events directly.

I also have another question. I selected participants who did not have health outcome and try to calculate person year by hand. I was wondering if there is any code I can use to get the sum of each product of each column* time: h:persist good person time=2*176+4*340+6*272+.......

Table of time by hear_p4cat
time	hear_p4cat
	h:persist good	h:poor to good	h:good to poor	h:persist poor	Total
2	176	25	18	19	238
4	340	29	39	68	476
6	272	37	33	51	393
8	319	21	33	36	409
10	229	22	26	30	307
12	247	24	17	31	319
14	1275	63	79	143	1560
Total	2858	221	245	378	3702

Thanks!

[ballardw]

Please provide example data in the form of data step code. Instructions here: https://communities.sas.com/t5/SAS-Communities-Library/How-to-create-a-data-step-version-of-your-dat... will show how to turn an existing SAS data set into data step code that can be pasted into a forum code box using the </> icon or attached as text to show exactly what you have and that we can test code against.

If you can't manage that at least post the example as simple text in a text box. That particular tabular layout is not worth trying to write a data step with.

My first thought would be Proc Means/ summary with your Time variable as a Weight variable and then request a Sum for the other variables. DO not include the Total row, if you have such in your actual data set, as it is obviously not a numeric variable and a Weight variable must be numeric.