Frequencies for first 10,000 rows of prescr3 variable in nhamcsed2010 dataset :

            Prescription status code |      Freq.     Percent        Cum.
-------------------------------------+-----------------------------------
                   prescription drug |      2,491       24.91       24.91
                nonprescription drug |         76        0.76       25.67
                        undetermined |         39        0.39       26.06
prescription or nonprescription drug |        773        7.73       33.79
                                   . |      6,621       66.21      100.00
-------------------------------------+-----------------------------------
                               Total |     10,000      100.00

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