data schiz;
  infile 'case0202.txt';
  input unaff aff;
  diff =  unaff - aff;

proc means mean std stderr t prt clm;
  var diff;
  title 'Paired data: t-test and 95% confidence interval';
run;
                     
proc univariate;
  var diff;
  title 'Paired t-test and nonparametric tests using proc univariate';
run;