Frequencies for first 10,000 rows of drug2cl3 variable in nhamcsopd2005 dataset :

          ndc code #3 for medication #2 |      Freq.     Percent        Cum.
----------------------------------------+-----------------------------------
               calcium channel blockers |          1        0.01        0.01
                       topical steroids |          1        0.01        0.02
                        anticonvulsants |         18        0.18        0.20
                cycloplegics/mydriatics |          1        0.01        0.21
ocular anti-infective/anti-inflammatory |          3        0.03        0.24
              miscellaneous ophthalmics |          7        0.07        0.31
                                  nsaid |          1        0.01        0.32
                           antipyretics |         66        0.66        0.98
         antiasthmatics/bronchodilators |          3        0.03        1.01
   antitussives/expectorants/mucolytics |          1        0.01        1.02
                         antihistamines |         25        0.25        1.27
                          cold remedies |         19        0.19        1.46
                    pharmaceutical aids |          1        0.01        1.47
                          surgical aids |         17        0.17        1.64
                                      . |      9,836       98.36      100.00
----------------------------------------+-----------------------------------
                                  Total |     10,000      100.00

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