Exploring the impact of age on the predictive power of the National Early Warning score (NEWS) 2, and long-term prognosis among patients reviewed by a Rapid Response Team: A prospective, multi-centre study

Aim

To explore the impact of age on the discriminative ability of the National Early Warning Score (NEWS) 2 in prediction of unanticipated Intensive Care Unit (ICU) admission, in-hospital cardiac arrest (IHCA) and mortality within 24 hours of Rapid Response Team (RRT) review. Furthermore, to investigate 30- and 90-day mortality, and the discriminative ability of NEWS 2 in prediction of long-term mortality among RRT-reviewed patients.

Methods

Prospective, multi-centre study based on 830 complete cases. Data was collected by RRTs in 24 hospitals between October 2019, and January 2020. All NEWS 2 scores were uniformly calculated by the study team. Age was analysed as a continuous variable, in a spline regression model, and categorized into five different models, subsequently explored as additive variables to NEWS 2. The discriminative ability of NEWS 2 was evaluated using the Area under the receiver operating characteristics (AUROC).

Results

The discriminative ability of NEWS 2 alone in predicting 30-day mortality was weak. Adding age as a covariate improved the predictive performance (AUROC 0.66, 0.62–0.70 to 0.70, 0.65–0.73, p = 0.01, 95 % Confidence Interval). There were differences across age groups, with the best discriminative ability identified among patients aged 45-54 years. The 30- and 90-day mortality was 31% and 33% respectively.

Results

Adding age as a covariate improved the discriminative ability of NEWS 2 in the prediction of 30-day mortality among RRT-reviewed patients, with variations observed across age categories. The long- term prognosis of RRT-reviewed patients was poor.