Frequencies for first 10,000 rows of rx5v1c2 variable in nhamcsopd2006 dataset :

   for rx5, level 1 of multum |
             drug category #2 |      Freq.     Percent        Cum.
------------------------------+-----------------------------------
              Anti-infectives |         13        0.13        0.13
        Cardiovascular agents |         13        0.13        0.26
Central nervous system agents |         44        0.44        0.70
        Coagulation modifiers |         44        0.44        1.14
                     Hormones |          6        0.06        1.20
         Miscellaneous agents |         14        0.14        1.34
         Nutritional products |          5        0.05        1.39
           Respiratory agents |         28        0.28        1.67
               Topical agents |          2        0.02        1.69
     Psychotherapeutic agents |          2        0.02        1.71
         Immunological agents |          1        0.01        1.72
             Metabolic agents |         11        0.11        1.83
                            . |      9,817       98.17      100.00
------------------------------+-----------------------------------
                        Total |     10,000      100.00

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