Frequencies for first 10,000 rows of rx2v1c1 variable in nhamcsed2006 dataset :

   for rx2, level 1 of multum |
             drug category #1 |      Freq.     Percent        Cum.
------------------------------+-----------------------------------
              anti-infectives |        778        7.78        7.78
              antineoplastics |          1        0.01        7.79
                  biologicals |          1        0.01        7.80
        cardiovascular agents |        270        2.70       10.50
central nervous system agents |      2,262       22.62       33.12
        coagulation modifiers |         41        0.41       33.53
      gastrointestinal agents |        259        2.59       36.12
                     hormones |        136        1.36       37.48
         miscellaneous agents |        112        1.12       38.60
         nutritional products |        173        1.73       40.33
           respiratory agents |        524        5.24       45.57
               topical agents |        160        1.60       47.17
        alternative medicines |          1        0.01       47.18
     psychotherapeutic agents |         22        0.22       47.40
         immunological agents |         52        0.52       47.92
            radiologic agents |          7        0.07       47.99
             metabolic agents |         39        0.39       48.38
           pharmaceutical aid |          1        0.01       48.39
                            . |      5,161       51.61      100.00
------------------------------+-----------------------------------
                        Total |     10,000      100.00

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