Frequencies for first 10,000 rows of comstat1 variable in nhamcsed2008 dataset :

          for rx1, |
composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      6,452       64.52       64.52
  combination drug |      1,385       13.85       78.37
                 . |      2,163       21.63      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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