Frequencies for first 10,000 rows of rx7v1c1 variable in nhamcsed2006 dataset :

   for rx7, level 1 of multum |
             drug category #1 |      Freq.     Percent        Cum.
------------------------------+-----------------------------------
              anti-infectives |         16        0.16        0.16
              antineoplastics |          1        0.01        0.17
        cardiovascular agents |         19        0.19        0.36
central nervous system agents |         35        0.35        0.71
        coagulation modifiers |          8        0.08        0.79
      gastrointestinal agents |          8        0.08        0.87
                     hormones |          4        0.04        0.91
         miscellaneous agents |          3        0.03        0.94
         nutritional products |          5        0.05        0.99
           respiratory agents |          3        0.03        1.02
               topical agents |          2        0.02        1.04
     psychotherapeutic agents |          4        0.04        1.08
         immunological agents |          3        0.03        1.11
             metabolic agents |          4        0.04        1.15
                            . |      9,885       98.85      100.00
------------------------------+-----------------------------------
                        Total |     10,000      100.00

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