Sorry if it is second posting. But I received 2 messages that my mail failed.

Hi,Karen! If you want to have one record per mother and keep mother age at each baby's birth you have to set a limit -MAXCHILD-i,e. maximal number of children. The program will look like the following(not tested): data mothers; merge mothers babies; by motherid; bir_age=(child_birth_date - mother_birth_date)/365.25; *this is the convention for calculating age in SAS Language manual; run; proc sort data=mothers; by motherid;by motherid child_birth_date;run; %let MAXCHILD=10; data mothers; set mothers;by motherid; array b_age b_age1-b_age&MAXCHILD; retain b_age1-b_age&MAXCHILD numchild; if first.motherid then do ;numchild=0; do over b_age; b_age=.;end; end; numchild+1; b_age(numchild)=bir_age; drop bir_age; if last.motherid; run;

Sincerely

Victor Kamensky

Programmer

Albert Einstein College of Medicine

At 09:21 AM 7/2/97 EST, you wrote: >I'm having trouble thinking logically about this. >I have a file with baby info, 1 record per baby. Included in this file >is a mother id. I have another file with mother info, 1 record per mother. >Because of multiple births, there are more babies than mothers. I want >to calculate mother age at baby's birth and need to get baby's birthday >out of the baby file. When I merge the two files by mother id, I get >extra mother records for the multiple births. >How do I merge the files and keep only 1 record per mother id in the >merged file? > >And while I'm writing, is there a convention for calculating age? A few >days off for leap years doesn't matter here, but as long as I'm writing >the program, might as well be exact. > >Thanks for any help. >Karen Olson >Children's Hospital, Boston, MA >olson_k@a1.tch.harvard.edu > >