Frequencies for first 10,000 rows of comstat1 variable in nhamcsed2015 dataset 

Composition status |
          code for |
     medication #1 |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |      6,795       67.95       67.95
  Combination drug |      1,104       11.04       78.99
      Undetermined |         90        0.90       79.89
                 . |      2,011       20.11      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 20 Nov 2017