Descriptors of Sepsis Using the Sepsis-3 Criteria

A Cohort Study in Critical Care Units Within the U.K. National Institute for Health Research Critical Care Health Informatics Collaborative

Anoop D. Shah, PhD, MRCP, FFCI; Niall S. MacCallum, PhD, MRCP, FRCA; Steve Harris, PhD, FRCA; David A. Brealey, PhD, MRCP, FRCA; Edward Palmer, MBBS, BSc(Hons), FRCA, MFCI; James Hetherington, PhD, FBCS; Sinan Shi, MSc; David Perez-Suarez, PhD; Ari Ercole, PhD; Peter J. Watkinson, MD, ChB, MRCP; Andrew Jones, MD, MRCP; Simon Ashworth, BSc(Hons), BM, MRCP(UK), FRCA, FFICM; Richard Beale, FRCA, FFICM; Stephen J. Brett, MD, FRCA, FFICM; Mervyn Singer, MD, FRCP


Crit Care Med. 2021;49(11):1883-1894. 

In This Article

Abstract and Introduction


Objectives: To describe the epidemiology of sepsis in critical care by applying the Sepsis-3 criteria to electronic health records.

Design: Retrospective cohort study using electronic health records.

Setting: Ten ICUs from four U.K. National Health Service hospital trusts contributing to the National Institute for Health Research Critical Care Health Informatics Collaborative.

Patients: A total of 28,456 critical care admissions (14,332 emergency medical, 4,585 emergency surgical, and 9,539 elective surgical).

Measurements and Main Results: Twenty-nine thousand three hundred forty-three episodes of clinical deterioration were identified with a rise in Sequential Organ Failure Assessment score of at least 2 points, of which 14,869 (50.7%) were associated with antibiotic escalation and thereby met the Sepsis-3 criteria for sepsis. A total of 4,100 episodes of sepsis (27.6%) were associated with vasopressor use and lactate greater than 2.0 mmol/L, and therefore met the Sepsis-3 criteria for septic shock. ICU mortality by source of sepsis was highest for ICU-acquired sepsis (23.7%; 95% CI, 21.9–25.6%), followed by hospital-acquired sepsis (18.6%; 95% CI, 17.5–19.9%), and community-acquired sepsis (12.9%; 95% CI, 12.1–13.6%) (p for comparison less than 0.0001).

Conclusions: We successfully operationalized the Sepsis-3 criteria to an electronic health record dataset to describe the characteristics of critical care patients with sepsis. This may facilitate sepsis research using electronic health record data at scale without relying on human coding.


Sepsis is a leading cause of mortality and critical illness worldwide[1] and a common reason for admission to ICUs, but it is often hard to identify, with no reliable diagnostic test.[2] Sepsis is defined as a dysregulated and deleterious host response to infection leading to organ dysfunction,[3] though this represents an umbrella syndrome covering a host of biological and clinical phenotypes.

The original 1992 criteria for sepsis[4,5] were based on the presence of two or more Systemic Inflammatory Response Syndrome criteria related to suspected or proven infection. However, ill-defined criteria for organ dysfunction ("severe sepsis") and septic shock led to a reported incidence and mortality rate that could vary three- to 10-fold.[6] The 2016 "Sepsis-3" Task Force[3] aimed to improve the consistency of reporting by offering specific clinical criteria that characterized organ dysfunction and shock with a clearer association with mortality. Sepsis-3 uses a change in the Sequential Organ Failure Assessment (SOFA) score of 2 or more points associated with the acute infectious episode as the clinical criterion for new organ dysfunction.[7,8]

It has been difficult to describe the epidemiology of sepsis using routine data because clinical coding data do not capture all cases[9,10] and are affected by coding practices that have changed over time.[11,12] Objective definitions of sepsis based on clinical parameters in electronic health records (EHRs) have been found to provide more stable disease estimates over time than coding data.[13,14] Such studies rely on detailed hospital health records being available for research at scale, which has not previously been the case in the United Kingdom.

In this study, we sought to describe the epidemiology of sepsis and patterns of antibiotic use in ICUs by operationalizing the Sepsis-3 definitions within EHRs. We used data from ICUs within four large National Health Service (NHS) Hospital Trusts with Biomedical Research Centers, which contribute to the National Institute of Health Research (NIHR) Critical Care theme of the Health Informatics Collaborative (CC-HIC).