Frequencies for first 10,000 rows of rx4v1c1 variable in nhamcsopd2006 dataset :

   for rx4, level 1 of multum |
             drug category #1 |      Freq.     Percent        Cum.
------------------------------+-----------------------------------
              Anti-infectives |         85        0.85        0.85
              Antineoplastics |         27        0.27        1.12
                  Biologicals |          2        0.02        1.14
        Cardiovascular agents |        335        3.35        4.49
Central nervous system agents |        459        4.59        9.08
        Coagulation modifiers |         35        0.35        9.43
      Gastrointestinal agents |        149        1.49       10.92
                     Hormones |         78        0.78       11.70
         Miscellaneous agents |         43        0.43       12.13
         Nutritional products |        138        1.38       13.51
           Respiratory agents |        171        1.71       15.22
               Topical agents |         88        0.88       16.10
        Alternative medicines |         21        0.21       16.31
     Psychotherapeutic agents |        152        1.52       17.83
         Immunological agents |         37        0.37       18.20
            Radiologic agents |          2        0.02       18.22
             Metabolic agents |        197        1.97       20.19
           Pharmaceutical aid |          1        0.01       20.20
                            . |      7,980       79.80      100.00
------------------------------+-----------------------------------
                        Total |     10,000      100.00

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