How do you merge lines in a single dataset with some duplicate values? - merge

Question

I am analyzing a medical record dataset where the patients were screened for STIs at 4 different times points. The data manager created a line per patient per STI for each time period. I want to merge the dataset so there is one line per patient at each time point with all of the diagnosed STI listed.
I created the new variables to capture each STI that would be listed under the Dx variable, but I can't figure out how to merge data within the same dataset so there is only one per patient at each timepoint.
data dx;
set dx;
if dx='ANOGENITAL WARTS (CONDYLOMATA ACUMINATA)' then MRWarts=1;
if dx='CHLAMYDIA' then MRCHLAMYDIA=1;
if dx='DYSPLASIA (ANAL, CERVICAL, OR VAGINAL)' then MRDYSPLASIA=1;
if dx='GONORRHEA' then MRGONORRHEA=1;
if dx='HEPATITIS B (HBV)' then MRHEPB=1;
if dx='HUMAN PAPILLOMAVIRUSES (HPV)-ANY MANIFESTATION' then MRHPV=1;
if dx='PEDICULOSIS PUBIS' then MRPUBIS=1;
if dx='SYPHILIS' then MRSYPHILIS=1;
if dx='TRICHOMONAS VAGINALIS' then MRTRICHOMONAS=1;
run;
Image of data structure I am looking for

Answer 1

taking the sample dataset that you provided in the image, you can use simple transpose for desired outcome.
data have;
input Pt_ID interval_round DX $10.;
datalines;
4 1 HIV
4 1 Warts
3 1 HIV
5 2 Chlamydia
;
run;
proc sort data=have1; by Pt_Id; run;
proc transpose data=have1 out=want(drop=_NAME_);
by Pt_Id;
id Dx;
var interval_round;
run;
proc print data=want; run;
Now this code will create all variables except interval_round, Say for example - a patient was screened for HIV in round 1 and Warts for round 2. Technically it should have only one row .. so how would you represent the interval_round then?