Hello,
This is a follow-up question to a solution posted here. I'm trying to calculate cumulative exposure history before disease diagnosis, given age of exposure onset (age), age of disease diagnosis (dxAge), and exposure type (Extype).
My program looks like this:
data have;
format id age dxAge Extype 3.;
input id age dxAge Extype;
cards;
1 18 48 1
1 25 48 1
1 48 48 1
1 50 48 1
1 52 48 . *The last line is current age;
;
run;
proc sort data=have;
by id descending age;
run;
data new;
set have;
by id;
retain found lastAge;
if first.id then do;
found = 0;
lastAge = 0;
end;
if lastAge gt 0 then
time = lastAge - age;
else
time = 0;
if dxAge gt 0 then do; *Lag exposure time to one year before diagnosis;
if not(found) then do;
if dxAge - age gt 1 then do;
found = 1;
lagTime = (dxAge - age) - 1;
end;
else
lagTime = 0;
end;
else
lagTime = time;
end;
else
lagTime = 0;
lastAge = age;
run;
proc sort data=new;
by id age;
run;
However, in some instances I have multiple lines of exposure time (e.g., multiple exposure types) for the same age:
data have;
format id age dxAge Extype 3.;
input id age dxAge Extype;
cards;
1 18 48 1
1 18 48 2
1 18 48 3
1 25 48 1
1 48 48 1
1 50 48 1
1 52 48 .
;
run;
My desired output looks like this:
ID Age DxAge Extype Lagtime
1 18 48 1 7
1 18 48 2 7
1 18 48 3 7
1 25 48 1 22
1 48 48 1 0
1 50 48 1 0
1 52 48 . 0
Running the program above only counts the first line of exposure time (25-18=7 years) and sets the next lines to 0. The cumulative time from age 18 to 25 should be 7*3=21 years. Could anyone please suggest a fix for this? Thank you.
