Frequencies for first 10,000 rows of comstat2 variable in nhamcsopd2006 dataset :

          for rx2, |
composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
Single entity drug |      3,795       37.95       37.95
  Combination drug |        531        5.31       43.26
                 . |      5,674       56.74      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

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