topic Re: calculating age difference between SAS and SPSS in SAS Programming

calculating age difference between SAS and SPSS

archibald — Mon, 20 Jun 2016 17:55:46 GMT

Hi,

Using this syntax in SAS Age= (graduationdate-dob)/365.25;

and using the equivalent in spss Compute Age= (graduationdate-dob)/365.25.

I get the same exact result. In SPSS, the present code takes into account leap year.

but the issue is in SAS to accurately calculate age while taking into acount leap year the folllowing should be used

syntax 3- Age= ('year' dob, graduationdate, 'continuous')

OR syntax 3- Age= intck('year', dob, graduationdate) - (put(dob, mmddyy4.) > put(graduationdate, mmddyy4.)).

However results from syntax3 or syntax4 are not similar to that of the SPSS code.

Does anyone know why this discrepancy? thanks.

Reeza — Mon, 20 Jun 2016 18:02:31 GMT

What SPSS code?

archibald — Mon, 20 Jun 2016 18:10:17 GMT

Compute Age= (graduationdate-dob)/365.25.

PGStats — Mon, 20 Jun 2016 18:42:33 GMT

Syntax 3 should be

Age = INTCK('year', dob, graduationdate, 'continuous')

dividing the number of days by 365.25 will give you the correct age sometimes but definitely not always.

Reeza — Mon, 20 Jun 2016 19:14:47 GMT

Then the SPSS code is not accounting for leap years. It is approximately, but not exactly so your SPSS numbers will be incorrect.

This is question was also asked yesterday,

Theres some links there that go over the differences between the methods and which one is correct.

archibald — Mon, 20 Jun 2016 19:50:02 GMT

good catch. INTCK shjould be includded.

Thanks!