Frequencies for first 10,000 rows of prescr7 variable in nhamcsed2010 dataset :

            Prescription status code |      Freq.     Percent        Cum.
-------------------------------------+-----------------------------------
                   prescription drug |        235        2.35        2.35
                nonprescription drug |          8        0.08        2.43
                        undetermined |          6        0.06        2.49
prescription or nonprescription drug |         70        0.70        3.19
                                   . |      9,681       96.81      100.00
-------------------------------------+-----------------------------------
                               Total |     10,000      100.00

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