Frequencies for first 10,000 rows of rx3v1c1 variable in nhamcsopd2006 dataset :

   for rx3, level 1 of multum |
             drug category #1 |      Freq.     Percent        Cum.
------------------------------+-----------------------------------
              Anti-infectives |        146        1.46        1.46
              Antineoplastics |         40        0.40        1.86
                  Biologicals |          5        0.05        1.91
        Cardiovascular agents |        456        4.56        6.47
Central nervous system agents |        679        6.79       13.26
        Coagulation modifiers |         35        0.35       13.61
      Gastrointestinal agents |        198        1.98       15.59
                     Hormones |        134        1.34       16.93
         Miscellaneous agents |         61        0.61       17.54
         Nutritional products |        197        1.97       19.51
           Respiratory agents |        268        2.68       22.19
               Topical agents |        151        1.51       23.70
        Alternative medicines |         18        0.18       23.88
     Psychotherapeutic agents |        220        2.20       26.08
         Immunological agents |         93        0.93       27.01
            Radiologic agents |         12        0.12       27.13
             Metabolic agents |        228        2.28       29.41
                            . |      7,059       70.59      100.00
------------------------------+-----------------------------------
                        Total |     10,000      100.00

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