Frequencies for first 10,000 rows of comstat2 variable in nhamcsed2008 dataset :

          for rx2, |
composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      4,508       45.08       45.08
  combination drug |        854        8.54       53.62
                 . |      4,638       46.38      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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