Clinical Instability Is a Sign of Severity of Illness: A Cohort Study

Authors

Murray M. Pollack, Department of Pediatrics, Division of Critical Care Medicine, Children's National Hospital and The George Washington University School of Medicine and Health Sciences, Washington, DC.
Eduardo Trujillo Rivera, Department of Bio-informatics, Children's National Hospital and The George Washington University School of Medicine and Health Sciences, Washington, DC.
Hiroki Morizono, Center for Genetic Medicine, Children's National Hospital Departments of Pediatrics, Genomics and Precision Medicine, The George Washington University School of Medicine and Health Sciences, Washington, DC.
Anita K. Patel, Department of Pediatrics, Division of Critical Care Medicine, Children's National Hospital and The George Washington University School of Medicine and Health Sciences, Washington, DC.

Document Type

Journal Article

Publication Date

9-1-2023

Journal

Pediatric critical care medicine : a journal of the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies

Volume

24

Issue

9

DOI

10.1097/PCC.0000000000003255

Abstract

OBJECTIVES: Test the hypothesis that within patient clinical instability measured by deterioration and improvement in mortality risk over 3-, 6-, 9-, and 12-hour time intervals is indicative of increasing severity of illness. DESIGN: Analysis of electronic health data from January 1, 2018, to February 29, 2020. SETTING: PICU and cardiac ICU at an academic children's hospital. PATIENTS: All PICU patients. Data included descriptive information, outcome, and independent variables used in the Criticality Index-Mortality. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: There were 8,399 admissions with 312 deaths (3.7%). Mortality risk determined every three hours using the Criticality Index-Mortality, a machine learning algorithm calibrated to this hospital. Since the sample sizes were sufficiently large to expect statical differences, we also used two measures of effect size, the proportion of time deaths had greater instability than survivors, and the rank-biserial correlation, to assess the magnitude of the effect and complement our hypothesis tests. Within patient changes were compared for survivors and deaths. All comparisons of survivors versus deaths were less than 0.001. For all time intervals, two measures of effect size indicated that the differences between deaths and survivors were not clinically important. However, the within-patient maximum risk increase (clinical deterioration) and maximum risk decrease (clinical improvement) were both substantially greater in deaths than survivors for all time intervals. For deaths, the maximum risk increase ranged from 11.1% to 16.1% and the maximum decrease ranged from -7.3% to -10.0%, while the median maximum increases and decreases for survivors were all less than ± 0.1%. Both measures of effect size indicated moderate to high clinical importance. The within-patient volatility was greater than 4.5-fold greater in deaths than survivors during the first ICU day, plateauing at ICU days 4-5 at 2.5 greater volatility. CONCLUSIONS: Episodic clinical instability measured with mortality risk is a reliable sign of increasing severity of illness. Mortality risk changes during four time intervals demonstrated deaths have greater maximum and within-patient clinical instability than survivors. This observation confirms the clinical teaching that clinical instability is a sign of severity of illness.

APA Citation

Pollack, Murray M.; Trujillo Rivera, Eduardo; Morizono, Hiroki; and Patel, Anita K., "Clinical Instability Is a Sign of Severity of Illness: A Cohort Study" (2023). GW Authored Works. Paper 3494.
https://hsrc.himmelfarb.gwu.edu/gwhpubs/3494

Department

Pediatrics