ViEWS-Towards a national early warning score for detecting adult inpatient deterioration

Aim of study: To develop a validated, paper-based, aggregate weighted track and trigger system (AWTTS) that could serve as a template for a national early warning score (EWS) for the detection of patient deterioration. Materials and methods: Using existing knowledge of the relationship between physiological data and adverse clinical outcomes, a thorough review of the literature surrounding EWS and physiology, and a previous detailed analysis of published EWSs, we developed a new paper-based EWS - VitalPAC (TM) EWS (VIEWS). We applied VIEWS to a large vital signs database (n = 198,755 observation sets) collected from 35,585 consecutive, completed acute medical admissions, and also evaluated the comparative performance of 33 other AWTTSs, for a range of outcomes using the area under the receiver-operating characteristics (AUROC) curve. Results: The AUROC (95% CI) for VIEWS using in-hospital mortality with 24 h of the observation set was 0.888(0.880-0.895). The AUROCs (95% CI) for the 33 other AWTTSs tested using the same outcome ranged from 0.803 (0.792-0.815) to 0.850(0.841-0.859). ViEWS performed better than the 33 other AWTTSs for all outcomes tested. Conclusions: We have developed a simple AWITS - ViEWS - designed for paper-based application and demonstrated that its performance for predicting mortality (within a range of timescales) is superior to all other published AWTTSs that we tested. We have also developed a tool to provide a relative measure of the number of "triggers" that would be generated at different values of EWS and permits the comparison of the workload generated by different AWTTSs. (C) 2010 Elsevier Ireland Ltd. All rights reserved.