A methodology to facilitate critical care research using multiple linked electronic, clinical and administrative health records at population scale

Introduction

Critical Care is a specialty in medicine providing a service for severely ill and high-risk patients who, due to the nature of their condition, may require long periods recovering after discharge. Consequently, focus on the routine data collection carried out in Intensive Care Units (ICUs) leads to reporting that is confined to the critical care episode and is typically insensitive to variation in individual patient pathways through critical care to recovery.A resource which facilitates efficient research into interactions with healthcare services surrounding critical admissions, capturing the complete patient's healthcare trajectory from primary care to non-acute hospital care prior to ICU, would provide an important longer-term perspective for critical care research.

Objective

To describe and apply a reproducible methodology that demonstrates how both routine administrative and clinically rich critical care data sources can be integrated with primary and secondary healthcare data to create a single dataset that captures a broader view of patient care.

Method

To demonstrate the INTEGRATE methodology, it was applied to routine administrative and clinical healthcare data sources in the Secure Anonymised Data Linking (SAIL) Databank to create a dataset of patients' complete healthcare trajectory prior to critical care admission. SAIL is a national, data safe haven of anonymised linkable datasets about the population of Wales.

Results

When applying the INTEGRATE methodology in SAIL, between 2010 and 2019 we observed 91,582 critical admissions for 76,019 patients. Of these, 90,632 (99%) had an associated non-acute hospital admission, 48,979 (53%) had an emergency admission, and 64,832 (71%) a primary care interaction in the week prior to the critical care admission.

Conclusion

This methodology, at population scale, integrates two critical care data sources into a single dataset together with data sources on healthcare prior to critical admission, thus providing a key research asset to study critical care pathways.

Validation of Cardiac Surgery Score (CASUS) in Postoperative Cardiac Patients

Introduction. Cardiac Surgery Score (CASUS) was introduced in 2005 as the first postoperative scoring system specific for patients who had cardiac surgery. Prior to this, European System for Cardiac Operative Risk Evaluation (EuroSCORE) has been used preoperatively, while Intensive Care National Audit and Research Centre Score (ICNARC) and Acute Physiology and Chronic Health Evaluation II (APACHE II) scores, which are widely used in general intensive care unit population, have been used to score cardiac patients postoperatively. The development of CASUS by Hekmat and colleagues for use in postoperative cardiac patients aims to change this. We wanted to validate CASUS against the well-established preoperative Logistic EuroSCORE, and postoperative APACHE II and ICNARC scores. Method. Institutional approval for this study was granted by the Audit and Clinical Governance Committee. We analyzed prospectively collected data of patients who had cardiac surgery in Castle Hill Hospital between January 2016 and September 2018. All patients who underwent surgery in the unit would have had Logistic EuroSCORE, APACHE, and ICNARC scores calculated as standard. CASUS was then calculated for these patients based on their day 1 postoperative variables. The scoring systems were compared and data presented as area under the receiver operating characteristic curve. Result. Our study shows that CASUS is the best predictor of mortality followed by ICNARC, Logistic EuroSCORE, and APACHE II. ICNARC score remains the most accurate predictor of renal and pulmonary complication followed by CASUS. Conclusion. CASUS is a useful scoring system in post-cardiac surgery patients. The accuracy of CASUS and ICNARC scores in predicting mortality, pulmonary, and renal complications are comparable.

Curation of an intensive care research dataset from routinely collected patient data in an NHS trust

In this data note we provide the details of a research database of 4831 adult intensive care patients who were treated in the Bristol Royal Infirmary, UK between 2015 and 2019. The purposes of this publication are to describe the dataset for external researchers who may be interested in making use of it, and to detail the methods used to curate the dataset in order to help other intensive care units make secondary use of their routinely collected data. The curation involves linkage between two critical care datasets within our hospital and the accompanying code is available online. For reasons of data privacy the data cannot be shared without researchers obtaining appropriate ethical consents. In the future we hope to obtain a data sharing agreement in order to publicly share the de-identified data, and to link our data with other intensive care units who use a Philips clinical information system.

Validation of the Intensive Care National Audit and Research Centre Scoring System in a UK Adult Cardiac Surgery Population

OBJECTIVE

The Intensive Care National Audit and Research Centre (ICNARC) scoring system was conceived in 2007, utilizing 12 physiologic variables taken from the first 24 hours of adult admissions to the general intensive care unit (ICU) to predict in-hospital mortality. The authors aimed to evaluate the ICNARC score in predicting mortality in cardiac surgical patients compared to established cardiac risk models such as logistic EuroSCORE as well as to the Acute Physiology and Chronic Health Evaluation (APACHE) II.

DESIGN

Retrospective analysis of data collected prospectively.

SETTING

Single-center study in a cardiac intensive care in a regional cardiothoracic center.

PARTICIPANTS

Patients undergoing cardiac surgery between January 2010 and June 2012.

METHODS

A total of 1,646 patients were scored preoperatively using the logistic EuroSCORE and postoperatively using ICNARC and APACHE II. Data for comparison of scoring systems are presented as area under the receiver operating characteristic curve.

MEASUREMENTS AND MAIN RESULTS

The mean age at surgery was 67 years±10.1. The mortality from all cardiac surgery was 3.2%. The mean logistic EuroSCORE was 7.31±10.13, the mean ICNARC score was 13.42±5.055, while the mean APACHE II score was 6.32±7.731. The c-indices for logistic EuroSCORE, ICNARC, and APACHE II were 0.801, 0.847 and 0.648, respectively.

CONCLUSION

The authors have, for the first time, validated the ICNARC score as a useful predictor of postoperative mortality in adult cardiac surgical patients. This could have implications for postoperative management, focusing the utilization of resources as well as a method to measure and compare performance in the cardiothoracic ICU.