Frequencies for first 10,000 rows of episode variable in nhamcsed2011 dataset :

Episode of care |      Freq.     Percent        Cum.
----------------+-----------------------------------
          Blank |        416        4.16        4.16
        Unknown |        367        3.67        7.83
  Initial visit |      8,564       85.64       93.47
Follow-up visit |        653        6.53      100.00
----------------+-----------------------------------
          Total |     10,000      100.00

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