Frequencies for first 10,000 rows of comstat8 variable in nhamcsed2010 dataset :

Composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |        146        1.46        1.46
  combination drug |         17        0.17        1.63
      undetermined |          4        0.04        1.67
                 . |      9,833       98.33      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016