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. 2021 Jul 13;3(7):e0474.
doi: 10.1097/CCE.0000000000000474. eCollection 2021 Jul.

Performance Analysis of the National Early Warning Score and Modified Early Warning Score in the Adaptive COVID-19 Treatment Trial Cohort

Christopher J Colombo  1   2 , Rhonda E Colombo  1   2   3 , Ryan C Maves  2   4 , Angela R Branche  5 , Stuart H Cohen  6 , Marie-Carmelle Elie  7 , Sarah L George  8 , Hannah J Jang  9 , Andre C Kalil  10 , David A Lindholm  2   11 , Richard A Mularski  12 , Justin R Ortiz  13 , Victor Tapson  14 , C Jason Liang  15
Affiliations

Performance Analysis of the National Early Warning Score and Modified Early Warning Score in the Adaptive COVID-19 Treatment Trial Cohort

Christopher J Colombo et al. Crit Care Explor. .

Abstract

We sought to validate prognostic scores in coronavirus disease 2019 including National Early Warning Score, Modified Early Warning Score, and age-based modifications, and define their performance characteristics.

Design: We analyzed prospectively collected data from the Adaptive COVID-19 Treatment Trial. National Early Warning Score was collected daily during the trial, Modified Early Warning Score was calculated, and age applied to both scores. We assessed prognostic value for the end points of recovery, mechanical ventilation, and death for score at enrollment, average, and slope of score over the first 48 hours.

Setting: A multisite international inpatient trial.

Patients: A total of 1,062 adult nonpregnant inpatients with severe coronavirus disease 2019 pneumonia.

Interventions: Adaptive COVID-19 Treatment Trial 1 randomized participants to receive remdesivir or placebo. The prognostic value of predictive scores was evaluated in both groups separately to assess for differential performance in the setting of remdesivir treatment.

Measurements and main results: For mortality, baseline National Early Warning Score and Modified Early Warning Score were weakly to moderately prognostic (c-index, 0.60-0.68), and improved with addition of age (c-index, 0.66-0.74). For recovery, baseline National Early Warning Score and Modified Early Warning Score demonstrated somewhat better prognostic ability (c-index, 0.65-0.69); however, National Early Warning Score+age and Modified Early Warning Score+age further improved performance (c-index, 0.68-0.71). For deterioration, baseline National Early Warning Score and Modified Early Warning Score were weakly to moderately prognostic (c-index, 0.59-0.69) and improved with addition of age (c-index, 0.63-0.70). All prognostic performance improvements due to addition of age were significant (p < 0.05).

Conclusions: In the Adaptive COVID-19 Treatment Trial 1 cohort, National Early Warning Score and Modified Early Warning Score demonstrated moderate prognostic performance in patients with severe coronavirus disease 2019, with improvement in predictive ability for National Early Warning Score+age and Modified Early Warning Score+age. Area under receiver operating curve for National Early Warning Score and Modified Early Warning Score improved in patients receiving remdesivir versus placebo early in the pandemic for recovery and mortality. Although these scores are simple and readily obtainable in myriad settings, in our data set, they were insufficiently predictive to completely replace clinical judgment in coronavirus disease 2019 and may serve best as an adjunct to triage, disposition, and resourcing decisions.

Keywords: Modified Early Warning Score; National Early Warning Score; age; coronavirus disease 2019; prognostic scores; severe acute respiratory syndrome coronavirus 2.

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Conflict of interest statement

Mention of trade name, commercial products, or organizations does not imply endorsement by the U.S. Government. Some of the authors (C.J.C., R.E.C., R.C.M., D.A.L., C.J.L.) are military service members or employees of the U.S. Government. This work was prepared as part of their official duties. Title 17 U.S.C. §105 provides that copyright protection under this title is not available for any work of the U.S. Government. Title 17 U.S.C. §101 defines a U.S. Government work as a work prepared by a military service member or employee of the U.S. Government as part of that person’s official duties. The investigators have adhered to the policies for protection of human subjects as prescribed in 45 CFR 46. This analysis used data from the Adaptive COVID-19 Treatment Trial (doi:10.1056/NEJMoa2007764). Collaborating investigators involved with collection of data during the ACTT-1 trial are noted in the Supplementary Appendix (http://links.lww.com/CCX/A699).

Figures

Figure 1.
Figure 1.
Illustration of baseline National Early Warning Score (NEWS) plotted against different end points, by placebo arm and remdesivir arm. Gray dots represent events and red dots represent censoring. Points are jittered to address overplotting.
Figure 2.
Figure 2.
Receiver operating characteristic (ROC) curves plotting false positives (FP) on the x-axis and true positives (TP) on the y-axis summarizing sensitivity and specificity of National Early Warning Score (NEWS), Modified Early Warning Score (MEWS), NEWS+age, and MEWS+age for the end points of 14-d mortality, recovery, and deterioration. The area under receiver operating curve for each curve is shown in the legend.
Figure 3.
Figure 3.
Receiver operating characteristic (ROC) curves plotting false positives (FP) on the x-axis and true positives (TP) on the y-axis summarizing sensitivity and specificity of average NEWS (NEWS avg), average MEWS (MEWS avg), change in NEWS (NEWS slope), and change in MEWS (MEWS slope) for the end points of 14-d mortality, recovery, and deterioration. The area under receiver operating curve for each curve is shown in the legend.
See this image and copyright information in PMC

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