Frequencies for first 10,000 rows of rx6v1c1 variable in nhamcsed2006 dataset :

   for rx6, level 1 of multum |
             drug category #1 |      Freq.     Percent        Cum.
------------------------------+-----------------------------------
              anti-infectives |         26        0.26        0.26
        cardiovascular agents |         32        0.32        0.58
central nervous system agents |         87        0.87        1.45
        coagulation modifiers |          2        0.02        1.47
      gastrointestinal agents |         33        0.33        1.80
                     hormones |         12        0.12        1.92
         miscellaneous agents |          4        0.04        1.96
         nutritional products |         12        0.12        2.08
           respiratory agents |         18        0.18        2.26
               topical agents |          4        0.04        2.30
     psychotherapeutic agents |          3        0.03        2.33
         immunological agents |          2        0.02        2.35
             metabolic agents |          5        0.05        2.40
                            . |      9,760       97.60      100.00
------------------------------+-----------------------------------
                        Total |     10,000      100.00

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