Frequencies for first 10,000 rows of dechal variable in drug2016q3 dataset :

Dechallenge |
      code, |
 indicating |
if reaction |
abated when |
       drug |
therapy was |
    stopped |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      6,478       64.78       64.78
          D |        180        1.80       66.58
          N |        131        1.31       67.89
          U |      2,302       23.02       90.91
          Y |        909        9.09      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 6 Apr 2017