From Mayo Clinic: Widely used track and trigger scores: Are they ready for automation in practice?

Resuscitation. 2014 Jan 7. pii: S0300-9572(13)00928-3. doi: 10.1016/j.resuscitation.2013.12.017. [Epub ahead of print]

Widely used track and trigger scores: Are they ready for automation in practice?

Romero-Brufau S1, Huddleston J2, Naessens J3, Johnson M3, Hickman J3, Morlan BW3, Jensen JB4, Caples SM5, Elmer JL6, Schmidt J6, Morgenthaler TI5,Santrach PJ7.

Author information

• 1Center for the Science of Health Care Delivery, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States.
• 2Center for the Science of Health Care Delivery, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States; Division of Hospital Internal Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States; Division of Health Care Policy and Research, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States. Electronic address: huddleston.jeanne@mayo.edu.
• 3Center for the Science of Health Care Delivery, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States; Division of Health CarePolicy and Research, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States.
• 4Department of Anesthesiology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States.
• 5Division of Pulmonary Medicine and Critical Care, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States.
• 6Department of Nursing, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States.
• 7Department of Laboratory Medicine and Pathology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States.

Abstract

INTRODUCTION:

Early Warning Scores (EWS) are widely used for early recognition of patient deterioration. Automated alarm/alerts have been recommended as a desirable characteristic for detection systems of patient deterioration. We undertook a comparative analysis of performance characteristics of common EWS methods to assess how they would function if automated.

METHODS:

We evaluated the most widely used EWS systems (MEWS, SEWS, GMEWS, Worthing, ViEWS and NEWS) and the Rapid Response Team (RRT) activation criteria in use in our institution. We compared their ability to predict the composite outcome of Resuscitation call, RRS activation or unplanned transfer to the ICU, in a time-dependent manner (3, 8, 12, 24 and 36h after the observation) by determining the sensitivity, specificity and positive predictive values (PPV). We used a large vital signs database (6,948,689 unique time points) from 34,898 unique consecutive hospitalized patients.

RESULTS:

PPVs ranged from less than 0.01 (Worthing, 3h) to 0.21 (GMEWS, 36h). Sensitivity ranged from 0.07 (GMEWS, 3h) to 0.75 (ViEWS, 36h). Used in an automated fashion, these would correspond to 1040-215,020 false positive alerts per year.

CONCLUSIONS:

When the evaluation is performed in a time-sensitive manner, the most widely used weighted track-and-trigger scores do not offer good predictive capabilities for use as criteria for an automated alarm system. For the implementation of an automated alarm system, better criteria need to be developed and validated before implementation.