The optimal threshold for prompt clinical review: An external validation study of the national early warning score.

When a patient has a national early warning score <5, we may assume that in the next 24 hr this patient is less likely to die unexpectedly, receive cardiopulmonary resuscitation or be transferred to the ICU. Because of the significant number of false positives when national early warning score is ≥5, hospitals should create workable guidelines for clinical practice.