Flag missing across all rows

[Cruise]

Hi folks,

I have a data with missing and I'd like to flag those individuals with missing data across all the rows as shown in the snippet below. 

Any suggestions appreciated. Thanks in advance. 

DATA HAVE;
INPUT ID DIAGNOSIS FLAG;
CARDS;  
1 3  0 
1 1  0
1 99 0
1 99 0
1 99 0
1 99 0
1 1  0
1 99 0
1 3  0
1 99 0
2 99 1
2 99 1
2 99 1
2 99 1
2 99 1
;
PROC PRINT; RUN; 

[PeterClemmensen]

So 99 is indicating 'missing' here?

[Cruise]

YES

[PeterClemmensen]

You can do something like this

data have;
input id diagnosis;
cards;  
1 3 
1 1 
1 99
1 99
1 99
1 99
1 1 
1 99
1 3 
1 99
2 99
2 99
2 99
2 99
2 99
;

data want(drop=c);
   c=0;
   do _n_ = 1 by 1 until (last.id);
      set have;
      by id;
      if diagnosis=99 then c=c+1;
   end;

   do until (last.id);
      set have;
      by id;
      flag=ifn(c=_N_, 1, 0);
      output;
   end;

run;

[novinosrin · Accepted solution]

DATA HAVE;
INPUT ID DIAGNOSIS;* FLAG;
CARDS;  
1 3  0 
1 1  0
1 99 0
1 99 0
1 99 0
1 99 0
1 1  0
1 99 0
1 3  0
1 99 0
2 99 1
2 99 1
2 99 1
2 99 1
2 99 1
;

proc sql;
create table want as
select *,sum(DIAGNOSIS=99)=n(id) as flag
from have 
group by id;
quit;

[Cruise]

Thanks both of you. Excellent solutions.