Frequencies for first 10,000 rows of rx3v1c2 variable in nhamcsed2006 dataset :

   for rx3, level 1 of multum |
             drug category #2 |      Freq.     Percent        Cum.
------------------------------+-----------------------------------
              anti-infectives |         47        0.47        0.47
              antineoplastics |          1        0.01        0.48
        cardiovascular agents |         35        0.35        0.83
central nervous system agents |        192        1.92        2.75
        coagulation modifiers |         28        0.28        3.03
         miscellaneous agents |         32        0.32        3.35
         nutritional products |          6        0.06        3.41
           respiratory agents |        114        1.14        4.55
               topical agents |         15        0.15        4.70
     psychotherapeutic agents |          7        0.07        4.77
             metabolic agents |          1        0.01        4.78
                            . |      9,522       95.22      100.00
------------------------------+-----------------------------------
                        Total |     10,000      100.00

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