Aggregate National Early Warning Score (NEWS) values are more important than high scores for a single vital signs parameter for discriminating the risk of adverse outcomes

Abstract

Introduction: The Royal College of Physicians (RCPL) National Early Warning Score (NEWS) escalates care to a doctor at NEWS values of ≥5 and when the score for any single vital sign is 3.

Methods: We calculated the 24-h risk of serious clinical outcomes for vital signs observation sets with NEWS values of 3, 4 and 5, separately determining risks when the score did/did not include a single score of 3. We compared workloads generated by the RCPL's escalation protocol and for aggregate NEWS value alone.

Results: Aggregate NEWS values of 3 or 4 (n=142,282) formed 15.1% of all vital signs sets measured; those containing a single vital sign scoring 3 (n=36,207) constituted 3.8% of all sets. Aggregate NEWS values of either 3 or 4 with a component score of 3 have significantly lower risks (OR: 0.26 and 0.53) than an aggregate value of 5 (OR: 1.0). Escalating care to a doctor when any single component of NEWS scores 3 compared to when aggregate NEWS values ≥5, would have increased doctors' workload by 40% with only a small increase in detected adverse outcomes from 2.99 to 3.08 per day (a 3% improvement in detection).

Conclusions: The recommended NEWS escalation protocol produces additional work for the bedside nurse and responding doctor, disproportionate to a modest benefit in increased detection of adverse outcomes. It may have significant ramifications for efficient staff resource allocation, distort patient safety focus and risk alarm fatigue. Our findings suggest that the RCPL escalation guidance warrants review.

Keywords: Failure to rescue; Hospital Rapid Response Team; Monitoring; Physiologic; Vital signs.