Frequencies for first 10,000 rows of comstat15 variable in nhamcsed2014 dataset :

Composition status |
          code for |
    medication #15 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |         56        0.56        0.56
  Combination drug |          1        0.01        0.57
      Undetermined |          1        0.01        0.58
                 . |      9,942       99.42      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 11 Apr 2017