Frequencies for first 10,000 rows of rx5v1c1 variable in nhamcsed2006 dataset :

   for rx5, level 1 of multum |
             drug category #1 |      Freq.     Percent        Cum.
------------------------------+-----------------------------------
              anti-infectives |         83        0.83        0.83
        cardiovascular agents |         46        0.46        1.29
central nervous system agents |        204        2.04        3.33
        coagulation modifiers |          9        0.09        3.42
      gastrointestinal agents |         43        0.43        3.85
                     hormones |         24        0.24        4.09
         miscellaneous agents |         12        0.12        4.21
         nutritional products |         35        0.35        4.56
           respiratory agents |         47        0.47        5.03
               topical agents |          9        0.09        5.12
             plasma expanders |          1        0.01        5.13
     psychotherapeutic agents |          3        0.03        5.16
         immunological agents |          4        0.04        5.20
             metabolic agents |          8        0.08        5.28
                            . |      9,472       94.72      100.00
------------------------------+-----------------------------------
                        Total |     10,000      100.00

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