Discrepancies of noninvasive ventilation (NIV) perceptions among intensive care unit (ICU) physicians, ICU nurses, patients, and their relatives. All items were scored on a scale from 1 to 10 (with “1” corresponding to “not at all” and “10” corresponding to “yes extremely”). *P < 0.05 with ICU physicians; £P < 0.05 with nurses; $P < 0.05 with patients. ^aData were obtained on 172 (56%) ICU physicians who have previously tried NIV. ^bData were obtained on 236 (32%) nurses who have previously tried NIV.