Frequencies for first 10,000 rows of rx8v1c1 variable in nhamcsopd2006 dataset :

   for rx8, level 1 of multum |
             drug category #1 |      Freq.     Percent        Cum.
------------------------------+-----------------------------------
              Anti-infectives |         25        0.25        0.25
              Antineoplastics |          6        0.06        0.31
                  Biologicals |          3        0.03        0.34
        Cardiovascular agents |        103        1.03        1.37
Central nervous system agents |        101        1.01        2.38
        Coagulation modifiers |         10        0.10        2.48
      Gastrointestinal agents |         46        0.46        2.94
                     Hormones |         23        0.23        3.17
         Miscellaneous agents |         15        0.15        3.32
         Nutritional products |         63        0.63        3.95
           Respiratory agents |         42        0.42        4.37
               Topical agents |         17        0.17        4.54
        Alternative medicines |         17        0.17        4.71
     Psychotherapeutic agents |         27        0.27        4.98
         Immunological agents |          8        0.08        5.06
             Metabolic agents |         74        0.74        5.80
                            . |      9,420       94.20      100.00
------------------------------+-----------------------------------
                        Total |     10,000      100.00

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