ObjectiveTo assess predictive performance of universal early warning scores (EWS) in disease subgroups and clinical settings.DesignSystematic review.Data sourcesMedline, CINAHL, Embase and Cochrane database of systematic reviews from 1997 to 2019.Inclusion criteriaRandomised trials and observational studies of internal or external validation of EWS to predict deterioration (mortality, intensive care unit (ICU) transfer and cardiac arrest) in disease subgroups or clinical settings.ResultsWe identified 770 studies, of which 103 were included. Study designs and methods were inconsistent, with significant risk of bias (high: n=16 and unclear: n=64 and low risk: n=28). There were only two randomised trials. There was a high degree of heterogeneity in all subgroups and in national early warning score (I2=72%–99%). Predictive accuracy (mean area under the curve; 95% CI) was highest in medical (0.74; 0.74 to 0.75) and surgical (0.77; 0.75 to 0.80) settings and respiratory diseases (0.77; 0.75 to 0.80). Few studies evaluated EWS in specific diseases, for example, cardiology (n=1) and respiratory (n=7). Mortality and ICU transfer were most frequently studied outcomes, and cardiac arrest was least examined (n=8). Integration with electronic health records was uncommon (n=9).ConclusionMethodology and quality of validation studies of EWS are insufficient to recommend their use in all diseases and all clinical settings despite good performance of EWS in some subgroups. There is urgent need for consistency in methods and study design, following consensus guidelines for predictive risk scores. Further research should consider specific diseases and settings, using electronic health record data, prior to large-scale implementation.PROSPERO registration numberPROSPERO CRD42019143141.

Objectives: To evaluate implementation of EHR-integrated NEWS2 in a cardiac care setting and a general hospital setting in the COVID-19 pandemic. Design: Thematic analysis of qualitative semi-structured interviews with purposefully sampled nurses and managers, as well as online surveys. Settings: Specialist cardiac hospital (St Bartholomews Hospital) and General teaching hospital (University College London Hospital). Participants: Eleven nurses and managers from cardiology, cardiac surgery, oncology, and intensive care wards (St Bartholomews) and medical, haematology and intensive care wards (UCLH) were interviewed and sixty-seven were surveyed online. Results: Three main themes emerged: (i) Implementing NEWS2 challenges and supports; (ii) Value of NEWS2 to alarm, escalate, particularly during the pandemic; and (iii) Digitalisation: EHR integration and automation. The value of NEWS2 was partly positive in escalation, yet there were concerns by nurses who undervalued NEWS2 particularly in cardiac care. Challenges, like clinicians' behaviours, lack of resources and training and the perception of NEWS2 value, limit the success of this implementation. Changes in guidelines in the pandemic have led to overlooking NEWS2. EHR integration and automated monitoring are improvement solutions that are not fully employed yet. Conclusion: Whether in specialist or general medical settings, the health professionals implementing EWS in healthcare face cultural and systems related challenges to adopting NEWS2 and digital solutions. The validity of NEWS2 in specialised settings and complex conditions is not yet apparent and requires comprehensive validation. EHRs integration and automation are powerful tools to facilitate NEWS2 if its principles are reviewed and rectified, and resources and training are accessible. Further examination of implementation from the cultural and automation domains are needed.