Frequencies for first 10,000 rows of role_cod variable in drug2011q4 dataset :

   Code for |
     drug's |
   reported |
    role in |
      event |      Freq.     Percent        Cum.
------------+-----------------------------------
          C |      5,302       53.02       53.02
          D |         14        0.14       53.16
          I |         64        0.64       53.80
         PS |      2,710       27.10       80.90
         SS |      1,910       19.10      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 18 Dec 2015