Frequencies for psi_11_postop_respfail_nustr variable in vwhqi_hosp_ahrq dataset :

PSI_11_POSTOP |
_RESPFAIL_NUM |
          _DC |      Freq.     Percent        Cum.
--------------+-----------------------------------
Not Available |      4,594      100.00      100.00
--------------+-----------------------------------
        Total |      4,594      100.00

by Jean Roth , jroth@nber.org , 16 Nov 2016