DATA a;

  INFILE 'esophaca.dat' ;

  INPUT  AgeFrom       AgeTo  

         AlcFrom       AlcTo

         TabacFr       TabacTo

         N_Cases       N_Ctls    ;


PROC PRINT (NOBS = 20);


DATA b (DROP = N_Cases N_ctls);

  SET a;

  Status = 1; count = N_Cases;
  IF count > 0 THEN OUTPUT;

  Status = 0; count = N_Ctls;
  IF count > 0 THEN OUTPUT;

PROC PRINT (NOBS = 40);

PROC SORT; BY Status;

PROC MEANS; by Status;
   FREQ count;