Frequencies for first 10,000 rows of comstat10 variable in nhamcsed2013 dataset :

Composition status |
          code for |
    medication #10 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |        112        1.12        1.12
  Combination drug |         14        0.14        1.26
      Undetermined |          1        0.01        1.27
                 . |      9,873       98.73      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 7 Nov 2016