Frequencies for first 10,000 rows of prescr1 variable in nhamcsed2013 dataset :

        Prescription status code for |
                       medication #1 |      Freq.     Percent        Cum.
-------------------------------------+-----------------------------------
                   Prescription drug |      4,343       43.43       43.43
                Nonprescription drug |        117        1.17       44.60
                        Undetermined |         93        0.93       45.53
Prescription or Nonprescription drug |      3,104       31.04       76.57
                                   . |      2,343       23.43      100.00
-------------------------------------+-----------------------------------
                               Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 7 Nov 2016