Frequencies for first 10,000 rows of prescr4 variable in nhamcsed2010 dataset :

            Prescription status code |      Freq.     Percent        Cum.
-------------------------------------+-----------------------------------
                   prescription drug |      1,465       14.65       14.65
                nonprescription drug |         36        0.36       15.01
                        undetermined |         23        0.23       15.24
prescription or nonprescription drug |        401        4.01       19.25
                                   . |      8,075       80.75      100.00
-------------------------------------+-----------------------------------
                               Total |     10,000      100.00

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