Frequencies for first 10,000 rows of ewarno variable in nhamcsopd2006 dataset :

   if yes, are |
there warnings |
       of drug |
 interactions? |      Freq.     Percent        Cum.
---------------+-----------------------------------
           Yes |      1,083       10.83       10.83
            No |        371        3.71       14.54
       Unknown |        579        5.79       20.33
Not applicable |      7,703       77.03       97.36
         Blank |        264        2.64      100.00
---------------+-----------------------------------
         Total |     10,000      100.00

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