Frequencies for first 10,000 rows of comstat6 variable in nhamcsed2007 dataset :

          for rx6, |
composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |        408        4.08        4.08
  combination drug |         55        0.55        4.63
                 . |      9,537       95.37      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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