remove duplicate by date and time

[monday89]

Current table

patientid	Event type	date	timepoint1	timepoint2	timepoint3	timepoint4
1	Baseline	1/28/2020	1200	600	1200
1	Daily	1/28/2020	1211		1211
1	Daily	1/29/2020	1221	1000	1221
2	Baseline	11/21/2019	1011	1359	1200	1200
2	Daily	11/21/2019	1011	1359	1200	1200
2	Daily	11/21/2019	1643	1645	1645	1644
2	Daily	11/21/2019	2225	2225	2225	2225
3	Baseline	11/25/2019	1440	1440	1440	1440
3	Daily	11/25/2019	1520	1520	1520	1520
4	Baseline	11/11/2019	1259	1300	1301	1300
4	Daily	11/11/2019	1259	1300	1301	1300
4	Daily	11/11/2019	1845	1847	1845	1845

within each same patient group, i would like to create a flag if date equals to next date within each patient AND all time points match, then baseline = 1 or 0

patientid	Event type	date	timepoint1	timepoint2	timepoint3	timepoint4	baseline
1	Baseline	1/28/2020	1200	600	1200		1
1	Daily	1/28/2020	1211		1211		0
1	Daily	1/29/2020	1221	1000	1221		0
2	Baseline	11/21/2019	1011	1359	1200	1200	1
2	Daily	11/21/2019	1011	1359	1200	1200	1
2	Daily	11/21/2019	1643	1645	1645	1644	0
2	Daily	11/21/2019	2225	2225	2225	2225	0
3	Baseline	11/25/2019	1440	1440	1440	1440	1
3	Daily	11/25/2019	1520	1520	1520	1520	0
4	Baseline	11/11/2019	1259	1300	1301	1300	1
4	Daily	11/11/2019	1259	1300	1301	1300	1
4	Daily	11/11/2019	1845	1847	1845	1845	0

I tried to divide daily and baseline tables into TWO different tables

and left join by date and then timepoints. i am really stuck

[ChrisNZ]

Only one row matches your criteria

patientid	Event type	date	timepoint1	timepoint2	timepoint3	timepoint4
1	Baseline	1/28/2020	1200	600	1200
1	Daily	1/28/2020	1211		1211
1	Daily	1/29/2020	1221	1000	1221
2	Baseline	11/21/2019	1011	1359	1200	1200
2	Daily	11/21/2019	1011	1359	1200	1200
2	Daily	11/21/2019	1643	1645	1645	1644
2	Daily	11/21/2019	2225	2225	2225	2225
3	Baseline	11/25/2019	1440	1440	1440	1440
3	Daily	11/25/2019	1520	1520	1520	1520
4	Baseline	11/11/2019	1259	1300	1301	1300
4	Daily	11/11/2019	1259	1300	1301	1300
4	Daily	11/11/2019	1845	1847	1845	1845

within each same patient group, i would like to create a flag if date equals to next date within each patient AND all time points match

[monday89]

Sorry I meant as in if group is Baseline or Daily (consequential) for the same patient AND all time points and dates match then baseline = 1 

[ChrisNZ]

> I meant as in if group is Baseline or Daily (consequential) for the same patient AND all time points and dates match then baseline = 1

This still doesn't make match your result.

[mkeintz]

It appears to me that:

1. Every ID begins with a baseline record, each ID has only one baseline record, and each baseline record has (unsurprisingly) the baseline flag set to one.  The programs below assumes so.
   
   
2. But for DAILY records, baseline=1 ONLY if all the timepoint values match the preceding record.  In your example the only daily records that fill this condition are the records immediate following the baseline record.  Is that true for your data?   Or can there be any other daily record that gets baseline=1 because its timepoint values match the preceding daily record?  If so, this program will flag such baseline records. 

The program below is untested (I'm not bothering to put your data into a DATA step):

data want;
  set have;
  by patientid;
  array tp timepoint: ;     /* Editted */
  baseline=1;                  /* Default to 1                              */
  do over tp;                  /* If any timepoint difference, convert to 0 */
    if lag(tp) ^= tp then baseline=0;
  end;
  if first.patientid=1 then baseline=1;
run;

If, however, the only daily records actually eligible for baseline=1 are the 2nd records of each patientid, whose timepoints match the baseline timepoints, then this more compact program will do:

data want;
  set have ;
  by patientid timepoint1 timepoint2 timepoint3 notsorted;
  baseline=0;                /* Editted additional statement */
  if first.patientid=1 then baseline=1;
  if lag(first.patientid)=1 and first.patientid=0 and first.timepoint3=0 then baseline=1;
run;

Notes:

1. The "notsorted" keyword at the end of the BY statement tells sas that the data are grouped, but not necessarily in ascending order for all the by-variables.
2. The "if first.patientid=1" test for whether the record-in-hand is the start of a patientid (which this program assumes is a baseline type of record).
3. The "if lag(first.patientid)=1 and first.patientid=0"  condition is true only for the 2nd record of each patientid  (Note the "and first.patientid=0" part is required in case the preceding record was the only record for the preceding patientid).
      and
   the "and first.timepoint3=0" condition is true only when all the by-variables in the current record match their values in the following record.

[Ksharp]

You need explain more details about your question.



data have;
infile cards expandtabs truncover;
input patientid	Eventtype $ date	: $20.  timepoint1	timepoint2	timepoint3	timepoint4;
cards;
1	Baseline	1/28/2020	1200	600	1200	 
1	Daily	1/28/2020	1211	 	1211	 
1	Daily	1/29/2020	1221	1000	1221	 
2	Baseline	11/21/2019	1011	1359	1200	1200
2	Daily	11/21/2019	1011	1359	1200	1200
2	Daily	11/21/2019	1643	1645	1645	1644
2	Daily	11/21/2019	2225	2225	2225	2225
3	Baseline	11/25/2019	1440	1440	1440	1440
3	Daily	11/25/2019	1520	1520	1520	1520
4	Baseline	11/11/2019	1259	1300	1301	1300
4	Daily	11/11/2019	1259	1300	1301	1300
4	Daily	11/11/2019	1845	1847	1845	1845
;

data want;
 set have;
 by patientid;
 retain _d _t1-_t4 .;
 baseline=0;
 if first.patientid  then do;
  call missing(of _:);
  if Eventtype='Baseline' then do;
  baseline=1;
  _d=date;_t1=timepoint1;_t2=timepoint2;
  _t3=timepoint3;_t4=timepoint4;
  end;
 end;
if patientid=lag(patientid) and _d=date and 
   _t1=timepoint1 and _t2=timepoint2 and
   _t3=timepoint3 and _t4=timepoint4 then baseline=1;
drop _:;
run;
 

proc print;run;
 

[unison · Accepted solution]

Maybe I'm mis-understanding but your written logic doesn't line up with what you've flagged as baseline=1.

If you are flagging for removal, does this remove the records you want out?

data have;
	input patientid Event_type :$15. date :mmddyy10. timepoint1 timepoint2 
		timepoint3 timepoint4;
	format date mmddyy10.;
	datalines;
1 Baseline 01/28/2020 1200 600 1200 .
1 Daily 01/28/2020 1211 . 1211 .
1 Daily 01/29/2020 1221 1000 1221 .
2 Baseline 11/21/2019 1011 1359 1200 1200
2 Daily 11/21/2019 1011 1359 1200 1200
2 Daily 11/21/2019 1643 1645 1645 1644
2 Daily 11/21/2019 2225 2225 2225 2225
3 Baseline 11/25/2019 1440 1440 1440 1440
3 Daily 11/25/2019 1520 1520 1520 1520
4 Baseline 11/11/2019 1259 1300 1301 1300
4 Daily 11/11/2019 1259 1300 1301 1300
4 Daily 11/11/2019 1845 1847 1845 1845
;
run;

proc sort data=have nodupkey out=want dupout=checkdups;
by patientid date timepoint:;
run;

Duplicates Removed:

patientid	Event_type	date	timepoint1	timepoint2	timepoint3	timepoint4
2	Daily	11/21/2019	1011	1359	1200	1200
4	Daily	11/11/2019	1259	1300	1301	1300

Want:

patientid	Event_type	date	timepoint1	timepoint2	timepoint3	timepoint4
1	Baseline	01/28/2020	1200	600	1200	.
1	Daily	01/28/2020	1211	.	1211	.
1	Daily	01/29/2020	1221	1000	1221	.
2	Baseline	11/21/2019	1011	1359	1200	1200
2	Daily	11/21/2019	1643	1645	1645	1644
2	Daily	11/21/2019	2225	2225	2225	2225
3	Baseline	11/25/2019	1440	1440	1440	1440
3	Daily	11/25/2019	1520	1520	1520	1520
4	Baseline	11/11/2019	1259	1300	1301	1300
4	Daily	11/11/2019	1845	1847	1845	1845