Performance and Improvement of Track and Trigger Scores Before Rescue and Transfer in the General Care Setting

This work aims to understand the performance of early warning scores calculated using intermittent vital signs to identify general deterioration in the medical/surgical setting and explore the feasibility of implementing near real-time scores using continuous monitoring as part of a systems approach to inpatient assessment.

This retrospective study used comparative trends and performance analyses to compare the ability of 4 early warning scores to identify patients requiring rescue and/or transfer to a higher level of care. Simulation was used to explore improvement in deterioration recognition with estimated scores calculated every 5 minutes as compared with those calculated using available intermittent vital signs to understand the potential impact of score calculation where continuous monitoring is available.

The National Early Warning Score performed better than other scores in identifying patients needing rescue and/or transfer to higher levels of care, with a sensitivity versus specificity analysis area under the curve value of 0.82. The National Early Warning Score also produced clinically acceptable misclassification ratios of 1:1 at scores of 6-7 or above. Simulation using this score, estimated every 5 minutes, improved detection of rescue and transfer events by over 5 hours on average.

Early warning scores can be used for the detection of general deterioration events and, if calculated frequently using parameters from continuous monitoring systems, can augment alarm-based continuous monitoring to create a system to further reduce unwitnessed arrests and deaths.