Once the numerators and denominators have the same structure (AREAKEY x AGECAT), they can be merged together, along with the ABSM data (by AREAKEY). For age cells within areas where no cases were reported, we set the numerator to zero.

This type of merging is an example of a SAS matched merge.

PROC SORT DATA=Step2a ;
BY AREAKEY AGECAT ;
RUN ;

DATA Step3 ;
MERGE Step1b (KEEP=AREAKEY AGECAT COUNT) Step2a ;
BY AREAKEY AGECAT ;

NUMER=COUNT ;
IF DENOM>0 THEN LOGDEN=LOG(DENOM) ;
ELSE LOGDEN=. ;
IF NUMER=. AND DENOM=>0 THEN NUMER=0 ;
IF DENOM>=0 THEN OUTPUT ;

DROP COUNT ;

RUN ;