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

      status of patient enrollment in a |
             disease management program |      Freq.     Percent        Cum.
----------------------------------------+-----------------------------------
                     Currently enrolled |        973        9.73        9.73
Ordered/advised to enroll at this visit |         74        0.74       10.47
                           Not enrolled |      1,624       16.24       26.71
                                Unknown |      2,137       21.37       48.08
                         Not applicable |      4,924       49.24       97.32
                                  Blank |        268        2.68      100.00
----------------------------------------+-----------------------------------
                                  Total |     10,000      100.00

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