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creating survival data

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Posts: 40

creating survival data

I have a longitudinal dataset with time variables (months) and event (0,1)...

 

How can I create a data table showing the time as when the event occurred and if the event did not occur the last follow-up time.

 

This is how the data looks.

 

ID        Time         Event

1          0                0

1          1                0

1          2                1

1          3                1

1          4                1

2          0                0

2          1                0

2          2                0

2          3                0

2          4                0

 

I want the data to look like:

ID      time       event

1        2            1

2        4            0 

 

Thanks

 

PROC Star
Posts: 7,467

Re: creating survival data

Here is one way:

 

data want (drop=_:);
  set have;
  retain _need;
  by id;
  if first.id then _need=1;
  if _need and (event eq 1 or last.id) then do;
    output;
    _need=0;
  end;
run;

HTH,

Art, CEO, AnalystFinder.com

 

Trusted Advisor
Posts: 1,018

Re: creating survival data

Another way:

 

data want;

  set have;

  by id event;

  if (first.event=1 and event=1) or (last.id=1 and event=0);

run;

 

 

This assumes that once a record with event=1 occurs, then event stays at 1 for the remaining records of the id.  And it assumes that data are sorted by ID.

 

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