Multicentre validation of the bedside paediatric early warning system score: a severity of illness score to detect evolving critical illness in hospitalised children

Abstract

Introduction: The timely provision of critical care to hospitalised patients at risk for cardiopulmonary arrest is contingent upon identification and referral by frontline providers. Current approaches require improvement. In a single-centre study, we developed the Bedside Paediatric Early Warning System (Bedside PEWS) score to identify patients at risk. The objective of this study was to validate the Bedside PEWS score in a large patient population at multiple hospitals.

Methods: We performed an international, multicentre, case-control study of children admitted to hospital inpatient units with no limitations on care. Case patients had experienced a clinical deterioration event involving either an immediate call to a resuscitation team or urgent admission to a paediatric intensive care unit. Control patients had no events. The scores ranged from 0 to 26 and were assessed in the 24 hours prior to the clinical deterioration event. Score performance was assessed using the area under the receiver operating characteristic (AUCROC) curve by comparison with the retrospective rating of nurses and the temporal progression of scores in case patients.

Results: A total of 2,074 patients were evaluated at 4 participating hospitals. The median (interquartile range) maximum Bedside PEWS scores for the 12 hours ending 1 hour before the clinical deterioration event were 8 (5 to 12) in case patients and 2 (1 to 4) in control patients (P < 0.0001). The AUCROC curve (95% confidence interval) was 0.87 (0.85 to 0.89). In case patients, mean scores were 5.3 at 20 to 24 hours and 8.4 at 0 to 4 hours before the event (P < 0.0001). The AUCROC curve (95% CI) of the retrospective nurse ratings was 0.83 (0.81 to 0.86). This was significantly lower than that of the Bedside PEWS score (P < 0.0001).

Conclusions: The Bedside PEWS score identified children at risk for cardiopulmonary arrest. Scores were elevated and continued to increase in the 24 hours before the clinical deterioration event. Prospective clinical evaluation is needed to determine whether this score will improve the quality of care and patient outcomes.

Figure 1

The receiver operating characteristic curve for the performance of the Bedside Paediatric Early Warning System score. Data are presented for 2,074 patients who were admitted to inpatient wards of four university-affiliated paediatric hospitals in a frequency-matched case-control study with two control patients per case. Case patients had either an immediate call to a resuscitation team or were urgently admitted to a paediatric intensive care unit (PICU) without a call to the resuscitation team. Control patients had neither. The maximum Bedside Paediatric Early Warning System score was calculated for the 12 hours ending 1 hour before the resuscitation team call or urgent PICU admission in case patients and for 12 hours in control patients.

Figure 2

Progression of Bedside Paediatric Early Warning System scores over time preceding clinically relevant events signifying clinical deterioration. Data are from 686 patients in the 24 hours before their event: either a call for immediate assistance from a resuscitation team or urgent admission to the paediatric intensive care unit. The graph represents the mean value of the maximum Bedside Paediatric Early Warning System (BPEWS) score from each of the studied patients for the defined four-hour periods. Repeated measures regression shows that the scores increased as the event grew nearer (P < 0.0001).

Figure 3

The relationship between the number of risk factors for near and actual cardiopulmonary arrest and the maximum Bedside Paediatric Early Warning System (BPEWS) score for the 12 hours ending 1 hour before immediate call to a resuscitation team or urgent paediatric intensive care unit admission in 686 case patients and for 12 hours in 1,388 control patients with no events. The maximum BPEWS score was not related to the number of risk factors in case patients and was positively associated in control patients (P < 0.0001).