Frequencies for first 10,000 rows of drug2cl3 variable in nhamcsed2005 dataset :

          ndc code #3 for medication #2 |      Freq.     Percent        Cum.
----------------------------------------+-----------------------------------
                          beta blockers |          1        0.01        0.01
                        anticonvulsants |         32        0.32        0.33
                cycloplegics/mydriatics |         10        0.10        0.43
ocular anti-infective/anti-inflammatory |          4        0.04        0.47
              miscellaneous ophthalmics |          1        0.01        0.48
       vertigo/motion sickness/vomiting |          1        0.01        0.49
                                  nsaid |          1        0.01        0.50
                           antipyretics |         61        0.61        1.11
         antiasthmatics/bronchodilators |          4        0.04        1.15
                    nasal decongestants |          1        0.01        1.16
                         antihistamines |        357        3.57        4.73
                          cold remedies |         18        0.18        4.91
                    pharmaceutical aids |          2        0.02        4.93
                          surgical aids |         66        0.66        5.59
                                      . |      9,441       94.41      100.00
----------------------------------------+-----------------------------------
                                  Total |     10,000      100.00

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