Frequencies for first 10,000 rows of prescr4 variable in nhamcsopd2004 dataset :

 prescription status |
 code for medication |
                  #4 |      Freq.     Percent        Cum.
---------------------+-----------------------------------
   prescription drug |      1,502       15.02       15.02
nonprescription drug |        247        2.47       17.49
        undetermined |        130        1.30       18.79
                   . |      8,121       81.21      100.00
---------------------+-----------------------------------
               Total |     10,000      100.00

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