Frequencies for first 10,000 rows of prescr2 variable in nhamcsopd2006 dataset :

            for rx2, |
 prescription status |
                code |      Freq.     Percent        Cum.
---------------------+-----------------------------------
   Prescription drug |      3,517       35.17       35.17
Nonprescription drug |        447        4.47       39.64
        Undetermined |        362        3.62       43.26
                   . |      5,674       56.74      100.00
---------------------+-----------------------------------
               Total |     10,000      100.00

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