Vital Sign Volatility on Discharge Quadruples Mortality Risk

Researchers at the University of Texas (UT) Southwestern Medical Centre (Dallas, TX, USA) reviewed the electronic medical records (EMR) of 32,835 unique individuals from six Dallas-Fort Worth area hospitals to assess the association between vital sign instability at hospital discharge and post-discharge outcomes, including abnormalities in temperature, heart rate, blood pressure, respiratory rate, and oxygen saturation within 24 hours of discharge. Main measures included death or non-elective readmission within 30 days.

The results showed that 18.7% of the patients were discharged with one or more vital sign instabilities. And while 12.8% of individuals with no instabilities on discharge died or were readmitted, patients with one instability demonstrated a 16.9% tendency for adverse events, those with two instabilities showed a 21.2% tendency, and patients with three or more instabilities died or were readmitted 26% of the time. The presence of any instability was associated with higher risk-adjusted odds of either death or readmission, and was more strongly associated with death.


Patients with three or more instabilities had nearly four-fold increased odds of death and 40% increased odds of 30-day readmission compared to those with no instabilities. Analysis using logistic regression adjusted for predictors of 30-day death and readmission showed that having two or more vital sign instabilities at discharge had a positive predictive value of 22 % and positive likelihood ratio of 1.8 for 30-day death or readmission. The study was published on August 8, 2016, in Journal of General Internal Medicine.

“We found that nearly 1 in 5 hospitalized adults is discharged with one or more vital sign instabilities such as an elevated heart rate or low blood pressure,” said lead author Oanh Nguyen, MD, and assistant professor of internal medicine and clinical sciences. “This finding is an important patient safety issue because patients who had vital sign abnormalities on the day of discharge had higher rates of hospital readmission and death within 30 days, even after adjusting for many other risk factors.”

“At a time when people are developing complicated, black box computerized algorithms to identify patients at high risk of readmission, our study highlights that the stability of vital signs, something doctors review with their own eyes every day, is a simple, clinically objective means of assessing readiness and safety for discharge,” said senior author Ethan Halm, MD, director of the UT Southwestern Center for Patient-Centered Outcomes Research. “There's a good reason we call them vital signs. It is important for clinicians to look at all of the vital signs in the 24 hours prior to discharge, and not just the last set or the best ones in judging a patient's readiness for discharge.”

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University of Texas (UT) Southwestern Medical Centre