The effectiveness of the National Early Warning Score (NEWS) was assessed in two studies, both published online by Critical Care Medicine on Sept. 21.
The first study compared rates of ICU transfer and death before and after NEWS implementation in an affiliated U.S. tertiary care academic facility and community hospital. It included 42,402 adult patients hospitalized from March 1, 2014, through Feb. 28, 2015 (pre-implementation), and 42,920 patients hospitalized from Aug. 1, 2015, through July 31, 2016 (post-implementation). Compared to those treated before NEWS was used, the post-implementation patients did not show significant change in rates of ICU transfer (adjusted hazard ratio [HR], 0.94; 95% CI, 0.84 to 1.05) or death (HR, 0.90; 95% CI, 0.77 to 1.05). The authors noted that NEWS performed worse during the first 48 hours of admission, which was when most events occurred, than later in hospitalization. Use of NEWS caused 175,357 best practice advisories (BPAs) to fire, and BPAs were better at predicting an event within 12 hours among patients at the community hospital than at the academic center (7.4% vs. 2.2%). The majority of BPAs were ignored by nurses and created alert fatigue, the study also found.
The researchers later used hospital-specific data to retrain the NEWS and found that this improved its predictive performance. “The implementation of NEWS at our institution provides an important lesson on EWS that have been developed at an outside organization. An EWS performing well during validation at one center does not definitively translate into an optimized EWS at another institution, especially one with a different case mix index,” the authors said. They also recommended that hospitals implementing NEWS train their frontline staff before launch to expect false alarms and to consider the alert system more an “awareness” tool than a “go/no-go decision tool.”
The other study looked at the value of NEWS for predicting mortality in combination with measurement of soluble urokinase plasminogen activator receptor (suPAR). The observational cohort study included 17,312 acute medical patients consecutively admitted to a hospital in Denmark between Nov. 18, 2013, and Sept. 30, 2015. Admission NEWS was available for 16,244 patients, of whom 3.4% died in the hospital, 5.0% within 30 days, and 7.9% within 90 days. High suPAR was significantly associated with in-hospital, 30-day, and 90-day mortality. Adding suPAR to NEWS improved prediction of mortality in all three time periods.
The addition of suPAR was particularly significant in patients with low NEWS, among whom an elevated suPAR was associated with mortality risks similar to those of patients with higher NEWS. “This finding is of major clinical relevance as suPAR improves the current identification of high-risk patients among those with unaffected vital signs,” the authors said. “Using suPAR in combination with NEWS could potentially lead to clinical interventions among patients otherwise not considered urgent or at risk, thereby ultimately saving lives.” Other studies have looked at combining other biomarkers with NEWS, and use of multiple blood biomarkers with NEWS could provide the best predictive value, the study authors said.
A major limitation to implementing this idea is that it can take a long time to get suPAR results, they noted. “Faster determination of suPAR, for example, using turbidimetric methods rather than [enzyme-linked immunosorbent assay], is needed to increase the clinical value of suPAR in acute care and to implement a timely track-and-trigger system combining information on NEWS and suPAR,” the study said.