Usefulness of the National Early Warning Score for Risk Stratification of Stable Patients With Acute Symptomatic Pulmonary Embolism.

ABSTRACT

OBJECTIVES: The aim of this study was to assess the performance of the National Early Warning Score 2 (NEWS2) in predicting a short-term complicated outcome in stable patients with acute symptomatic pulmonary embolism (PE). We also studied the ability of the NEWS2 score compared with the simplified Pulmonary Embolism Severity Index (sPESI) for identifying low-risk patients with acute PE. METHODS: We performed a retrospective analysis of a prospective cohort composed of 848 patients with acute PE. The NEWS2 and the sPESI were calculated for each patient according to different clinical variables. We assessed the predictive accuracy of these scores for a 30-day complicated outcome using the C statistic, which was obtained by logistic regression models and ROC curves. We also assessed the test and performance characteristics of the low-risk versus high-risk categories of each prediction rule. RESULTS: Overall, 63 out of 848 patients died (7.4%; 95% confidence interval, 5.7%-9.2%) during the first month of follow-up. Both scores showed a similarly poor predictive value for 30-day complicated outcome (C statistic, 0.68 and 0.62). The sPESI classified fewer patients as low-risk (36.9% versus 44.5%; P<0.01). Compared with the NEWS2 score, the sPESI showed significantly higher sensitivity (92.1% versus 66.7%) and a better negative predictive value (98.4% versus 94.4%). CONCLUSION: Both scores provide similar information for stratifying the risk of a complicated outcome in stable patients with PE. The sPESI identified low-risk patients with PE better than the NEWS2 score.