How to track changing values for same ID across 5 datasets

[shasank]

Hi SAS community,

 I have 4 datasets that have data on same population across 6 time points.

I want to know how to perform the occurrence as show below.

Dataset 1

ID       Var 1

1           0

2           0

3           0

4           0

5           0

Dataset 2

ID       Var 1

1           0

2           0

3           1

4           0

5            0

Dataset 3

ID       Var 1

1           1

2           0

3           1

4           0

5           0

Dataset 4

ID       Var 1

1           1

2           0

3           0

4           1

5           0

I want to find of all the people who had an occurrence of 1 at-least once across the 4 time points or Datasets. 

[morgalr · Accepted solution]

I would merge all of the datasets, then use SQL.

proc sql;
  create table mergedSet as select * from Dataset1;
  insert into mergedSet values(select * from Dataset2);
  insert into mergedSet values(select * from Dataset3);
  insert into mergedSet values(select * from Dataset4);
  insert into mergedSet values(select * from Dataset5);

  select id, sum(var1)>0 as hasValue from mergedSet 
  group by id;
quit;

[Astounding]

A data step approach:

data want;

set dataset1 dataset2 dataset3 dataset4;

by ID;

where var1=1;

if first.ID;

keep ID;

run;