Prospective validation and refinement of the APPROACH cardiovascular surgical intensive care unit readmission score

Sanam Verma; Danielle A Southern; Ismail R Raslan; Colleen M Norris; Michelle M Graham; Sean M Bagshaw; Jayan Nagendran; Todd Maclure; Louise Y Sun; Wu Dat Chin; Sean van Diepen

doi:10.1016/j.jcrc.2019.08.018

Prospective validation and refinement of the APPROACH cardiovascular surgical intensive care unit readmission score

J Crit Care. 2019 Dec:54:117-121. doi: 10.1016/j.jcrc.2019.08.018. Epub 2019 Aug 9.

Authors

Affiliations

¹ Division of Cardiology, Department of Medicine, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada.
² O'Brien Institute for Public Health, Department of Community Health Sciences, University of Calgary, Calgary, Alberta, Canada.
³ Division of Cardiology, University of Toronto, Toronto, Canada.
⁴ Division of Cardiology, Department of Medicine, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada; School of Public Health, University of Alberta, Edmonton, Canada; Division of Cardiac Surgery, Department of Surgery, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada.
⁵ Department of Critical Care, University of Alberta, Edmonton, Alberta, Canada.
⁶ Division of Cardiac Surgery, Department of Surgery, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada.
⁷ Division of Cardiac Anesthesiology, University of Ottawa Heart Institute, School of Epidemiology and Public Health, University of Ottawa, Ottawa, Ontario, Canada; Institute for Clinical Evaluative Sciences, Ontario, Canada.
⁸ Division of Cardiology, Department of Medicine, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada; Department of Critical Care, University of Alberta, Edmonton, Alberta, Canada; Canadian Vigour Center, University of Alberta, Edmonton, Alberta, Canada. Electronic address: sv9@ualberta.ca.

PMID: 31421527
DOI: 10.1016/j.jcrc.2019.08.018

Abstract

Purpose: The APPROACH cardiovascular surgical intensive care unit (CVICU) readmission score has excellent discrimination and calibration for CVICU readmission after discharge to a surgical ward; however, it has not been prospectively validated.

Material and methods: In a prospective consecutive cohort of 805 patients ≥18 years admitted to the CVICU after coronary artery bypass and/or valvular surgery, the APPROACH CVICU readmission score was calculated at the time of discharge to a surgical ward. The study compared observed versus predicted CVICU readmission and the model discrimination was evaluated using AUC c-index. The incremental prognostic utility of 6 pre-specified prospectively collected respiratory (re-intubation, tracheostomy, oxygen at discharge) and hemodynamic variables (heart rate, systolic blood pressure, inotropes at discharge) were tested using net reclassification index (NRI) and integrated discrimination improvement (IDI).

Results: A total of 37 (4.6%) patients were readmitted to the CVICU. The median CVICU length of stay (9.0 vs 2.0 days, p < .001) and all-cause in-hospital mortality (8.1% vs 0.4%, p < .001) was higher among readmitted patients. The model had good discrimination (c-index = 0.748). Systolic blood pressure at discharge yielded the largest improvement in model discrimination (c-index = 0.782; Hosmer-Lemshow p = .749).

Conclusions: In a prospective validation cohort, the APPROACH CVICU readmission risk score had good discrimination and could be operationalized in future research and clinical practice.

Keywords: Cardiac surgery; Intensive care unit; Prediction model; Readmission; Validation.

Publication types

Research Support, Non-U.S. Gov't
Validation Study

MeSH terms

Aged
Area Under Curve
Coronary Artery Bypass* / mortality
Female
Humans
Intensive Care Units*
Middle Aged
Patient Discharge
Patient Readmission / statistics & numerical data*
Prognosis
Prospective Studies