Trajectories of the averaged abbreviated Vitalpac™ early warning score (AbEWS) and clinical course of 44,531 consecutive admissions hospitalized for acute medical illness

Background: It is not known how often, to what extent and over what time frame any early warning scores change, and what the implications of these changes are. Setting: Thunder Bay Regional Health Sciences Center, Ontario, Canada. Methods: The averaged vital signs measured over different time periods of 44,531 consecutive acutely ill medical admissions were determined and then combined to calculate the averaged abbreviated version of the Vitalpac™ early warning score (AbEWS) during each time period examined. Results: 18% of all in-hospital deaths within 30 days are in patients with a low AbEWS on admission. Those admitted with a low AbEWS are more likely to increase their score and those admitted with a high score are more likely to lower it. Paradoxically, patients who have an averaged score over the first 6. h in hospital that is lower than on admission have increased in-hospital mortality. Thereafter patients with an increase in the averaged score have almost twice the mortality of those with a decreased score. 4.7% of patients have a low averaged score on the day they die. Conclusion: AbEWS, without clinical judgment, cannot be used to detect those patients who do not need to be admitted to hospital or are suitable for discharge. A period of observation of at least 12. h is required before the trajectory of AbEWS is of prognostic value, and any "improvement" that occurs before this time may be illusory.