Frequencies for first 10,000 rows of drug1cl3 variable in nhamcsopd2005 dataset :

          ndc code #3 for medication #1 |      Freq.     Percent        Cum.
----------------------------------------+-----------------------------------
                         ace inhibitors |          2        0.02        0.02
                     topical analgesics |          1        0.01        0.03
                        anticonvulsants |         20        0.20        0.23
ocular anti-infective/anti-inflammatory |          9        0.09        0.32
              miscellaneous ophthalmics |         14        0.14        0.46
                   otic, topical (misc) |          1        0.01        0.47
                                  nsaid |          2        0.02        0.49
                           antipyretics |         62        0.62        1.11
   antitussives/expectorants/mucolytics |          1        0.01        1.12
                         antihistamines |         22        0.22        1.34
                          cold remedies |         16        0.16        1.50
                    pharmaceutical aids |          3        0.03        1.53
                          surgical aids |         72        0.72        2.25
                                      . |      9,775       97.75      100.00
----------------------------------------+-----------------------------------
                                  Total |     10,000      100.00

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