Frequencies for first 10,000 rows of drug1cl3 variable in nhamcsopd2003 dataset :

        drug class #3 for medication #1 |      Freq.     Percent        Cum.
----------------------------------------+-----------------------------------
                         ace inhibitors |          5        0.05        0.05
repl/regs of electrolytes/water balance |          1        0.01        0.06
                        anticonvulsants |         11        0.11        0.17
ocular anti-infective/anti-inflammatory |         25        0.25        0.42
                   otic, topical (misc) |          3        0.03        0.45
                           antipyretics |         37        0.37        0.82
                          antimalarials |          1        0.01        0.83
   antitussives/expectorants/mucolytics |          4        0.04        0.87
                         antihistamines |         14        0.14        1.01
                          cold remedies |          9        0.09        1.10
                    pharmaceutical aids |          2        0.02        1.12
                                      . |      9,888       98.88      100.00
----------------------------------------+-----------------------------------
                                  Total |     10,000      100.00

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