Dear List Subscribers,
I am working on the following problem and was wondering if
there is some command or set of commands to solve it:
Thank you in advance,
Eric
1. The dataset Cancer0 may have multiple dates of treatment (DATE) for
each patient (ID) with a given disease (SITE). Create a new dataset by keeping
only the record with earliest treatment date for each patient and disease site.
Dataset: Cancer0
OBS ID SEX AGE DODX SITE DATE
DOSE FRAC
1 1001 M 60 09NOV1986 LUNG 03JAN1987 5000
20
2 1001 M 60 09NOV1986 LUNG 03JAN1987 5000
20
3 1002 F 58 07JUN1993 BREAST 03FEB1994
4000 16
4 1002 F 58 07JUN1993 BREAST 05MAR1994 1000
5
5 1003 M 63 11OCT1990 LUNG 15DEC1990
3000 25
6 1003 M 63 11OCT1990 LUNG 18FEB1991
800 5
7 1003 M 59 24MAR1986 SKIN 23AUG1987
200 1
8 1004 F 48 30JUL1995 LARYNX 22SEP1995 3500
25
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