Frequencies for first 10,000 rows of rx6v1c1 variable in nhamcsopd2006 dataset :

   for rx6, level 1 of multum |
             drug category #1 |      Freq.     Percent        Cum.
------------------------------+-----------------------------------
              Anti-infectives |         33        0.33        0.33
              Antineoplastics |         18        0.18        0.51
                  Biologicals |          5        0.05        0.56
        Cardiovascular agents |        189        1.89        2.45
Central nervous system agents |        235        2.35        4.80
        Coagulation modifiers |         15        0.15        4.95
      Gastrointestinal agents |         79        0.79        5.74
                     Hormones |         46        0.46        6.20
         Miscellaneous agents |         23        0.23        6.43
         Nutritional products |         99        0.99        7.42
           Respiratory agents |         71        0.71        8.13
               Topical agents |         43        0.43        8.56
        Alternative medicines |         11        0.11        8.67
     Psychotherapeutic agents |         61        0.61        9.28
         Immunological agents |         12        0.12        9.40
            Radiologic agents |          2        0.02        9.42
             Metabolic agents |        111        1.11       10.53
           Pharmaceutical aid |          1        0.01       10.54
                            . |      8,946       89.46      100.00
------------------------------+-----------------------------------
                        Total |     10,000      100.00

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