Frequencies for first 10,000 rows of prescr4 variable in nhamcsed2013 dataset :

        Prescription status code for |
                       medication #4 |      Freq.     Percent        Cum.
-------------------------------------+-----------------------------------
                   Prescription drug |      1,288       12.88       12.88
                Nonprescription drug |         39        0.39       13.27
                        Undetermined |         30        0.30       13.57
Prescription or Nonprescription drug |        646        6.46       20.03
                                   . |      7,997       79.97      100.00
-------------------------------------+-----------------------------------
                               Total |     10,000      100.00

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