Article Text

Download PDFPDF
Development and implementation of a COVID-19 near real-time traffic light system in an acute hospital setting
  1. Marcela P Vizcaychipi1,
  2. Claire L Shovlin2,
  3. Alex McCarthy3,
  4. Alice Howard1,
  5. Alexander Brown3,
  6. Michelle Hayes1,
  7. Suveer Singh1,
  8. Linsey Christie1,
  9. Alice Sisson1,
  10. Roger Davies1,
  11. Christopher Lockie1,
  12. Monica Popescu1,
  13. Amandeep Gupta1,
  14. James Armstrong1,
  15. Hisham Said1,
  16. Timothy Peters1,
  17. Richard T Keays1
  18. ChelWest COVID-19 Consortium
    1. 1 Department of Anaesthesia and Intensive Care, Chelsea and Westminster Hospital NHS Foundation Trust, London, UK
    2. 2 National Heart and Lung Institute, Imperial College London, London, UK
    3. 3 Department of Information, Data Quality and Clinical Coding, Chelsea and Westminster Hospital NHS Foundation Trust, London, UK
    1. Correspondence to Dr Marcela P Vizcaychipi, Chelsea and Westminster Hospital NHS Trust, London, UK; Marcela.Vizcaychipi{at}


    Common causes of death in COVID-19 due to SARS-CoV-2 include thromboembolic disease, cytokine storm and adult respiratory distress syndrome (ARDS). Our aim was to develop a system for early detection of disease pattern in the emergency department (ED) that would enhance opportunities for personalised accelerated care to prevent disease progression. A single Trust’s COVID-19 response control command was established, and a reporting team with bioinformaticians was deployed to develop a real-time traffic light system to support clinical and operational teams. An attempt was made to identify predictive elements for thromboembolism, cytokine storm and ARDS based on physiological measurements and blood tests, and to communicate to clinicians managing the patient, initially via single consultants. The input variables were age, sex, and first recorded blood pressure, respiratory rate, temperature, heart rate, indices of oxygenation and C-reactive protein. Early admissions were used to refine the predictors used in the traffic lights. Of 923 consecutive patients who tested COVID-19 positive, 592 (64%) flagged at risk for thromboembolism, 241/923 (26%) for cytokine storm and 361/923 (39%) for ARDS. Thromboembolism and cytokine storm flags were met in the ED for 342 (37.1%) patients. Of the 318 (34.5%) patients receiving thromboembolism flags, 49 (5.3% of all patients) were for suspected thromboembolism, 103 (11.1%) were high-risk and 166 (18.0%) were medium-risk. Of the 89 (9.6%) who received a cytokine storm flag from the ED, 18 (2.0% of all patients) were for suspected cytokine storm, 13 (1.4%) were high-risk and 58 (6.3%) were medium-risk. Males were more likely to receive a specific traffic light flag. In conclusion, ED predictors were used to identify high proportions of COVID-19 admissions at risk of clinical deterioration due to severity of disease, enabling accelerated care targeted to those more likely to benefit. Larger prospective studies are encouraged.

    • emergency care systems
    • ventilation
    • thrombo-embolic disease
    • management
    • resuscitation
    • clinical care
    • infectious diseases
    • SARS

    This article is made freely available for use in accordance with BMJ’s website terms and conditions for the duration of the covid-19 pandemic or until otherwise determined by BMJ. You may use, download and print the article for any lawful, non-commercial purpose (including text and data mining) provided that all copyright notices and trade marks are retained.

    Statistics from

    Request Permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


    • Handling editor Edward Carlton

    • Collaborators Christopher Abela, MD dip Aesth Surg, FRCS Plast; Nisha Abraham-Thomas, MD; Ahmed Al-Hindawi, MD; Joanna Allam, MD FRCA; Mauro Arrica, MD FRCA; Christelle At, BSc; Javier Bargados, DipHE; Madeleine Beach, MD; Ian Beveridge, MD MRCP ; Neil Bodagh, MD; Peter Brooks, MD FRCA; Tom Browning, MD; Charo Bruce, MD; Kiran Chima, MD; James Cofie, City and Guilds; Harriet Collier, DipHE; Jonathan Collier, MD MA MFDS FRCS (OMFS) PhD; Declan Collins, MD FRCS Ed (Plast) PhD; Karen Collins, MD; Deirdre Conway, MD FRCA; Victoria Cordrey, MD; Caroline Cormack, MD FRCA; Alona Courtney, MD MSc MRCS; Mark Cox, MD FRCA; Sarah Cox, MD MRCP; Joshua Cuddihy, MD; Aleck Dalrymple, City and Guilds; Paramjeet Deol, MD FRCEM; Daryl Dob, MD FRCA; Juliet Dunn, MD FRCA; Jackeline Durbridge, MD FRCA; Simon Eccles, MD BDS FRCS (Plast); Jana Elbadaoui, DipHE; Fouad El-Hibri, MD; Muna Elsawahli, MD FRCA; Niveen El-Wahab, MD FRCA; Philippa Evans, MD; Noel Fee, DipHE; Emma Forman, MD; Gabriela Frunza, MD FRCA; Susan Gallagher, MD; Seth Galton, MD FRCA; Rea Ganatra, MD; Ajay Gandhi, MD; Gary Davies, MD FRCP; Clare Glicksman, MD; Joseph Gonzales, BSc; Lisa Greaney, MD BDS MFDS RCS FRCS OMFS; Samuel Greenhalgh, MD; Samuel Gregson, MD; Kevin Haire, MD FRCA; Sofia Hanger, MD; Seleena Haque, MD FRCA; Alison Hare, MD FRCA; Charlie Hensher, MD; Maria Herincs, MD; Alfred Hill, MD; Martine Howard, DipHE; Isabel Jones, MD FRCS (Plast); Andrzej Jandziol, MD FRCA; Mo Jawad, MD; John Jeans, MD; Jo Jennings, RGN; Ma Julve, MD; Jacyntha Kaur Khera, MD; Ami Kotecha, MD FRCA; Manisha Kulkarni, MD FRCA; Holly Lamont, MD; Corina Lee, MD FRCA; Phillip Lee, MD MRCP ; William Lever, MD; Alex Li, MD FRCA; Leda Lignos, MD; Ganga Liyanage, MD FRCA; Samantha Luff, BSc; Wanda Lui, BSc; Georgios Malietzis, MD MRCS PhD; Georgina Margiotta, MD; Zuzanna Matasova, BSc; Daniel McNaughton, MD; Ayo Meduoye, MD; Hannah Mills, MD; Alex Milne, BSc; Marco Morosin, MD; Sarah Morton, MD; Kenneth Murray, MD; Quentin Nelson, City and Guilds; Saaman Neriman, MD; Lisa Newell, DipHE; Bernard Norman, MD FRCA; Emma Norton, City and Guilds; Ben Nurdin, MD; Catherine Onuorah, MD; Leyla Osman, MD; Catherine O'Sullivan, MD; Chandni Parikh, MD; Saqib Parwez, MD; Shashank Patil, MD FRCEM; Sherina Peroos, MD; Elspeth Pickering, MD FRCA; Kris Pillay, MD FRCEM; Rob Pilling, MD FRCA; Martin Porter-Moore, City and Guilds; Olivera Potparic, MD FRCA; Kate Richardson, MD FRCA; John Roa, BSc; Eleanor Roderick, MD; Katherine Russell, MD; Atika Sabharwal, MD FRCA; Amee Samani, MD FRCA; Aleksei Sedov, DipHE; Natalie Silvey, MD; Jonathan Simon, MD; James Smellie, MD FRCS(Gen); Rebecca-Lea Smith, MD FRCA; Andrew Snell, City and Guilds; Jagdish Sokhi, MD; Ewelina Szubert, DipHE; Ben Thomas, MD FRCA; John Thornton, MD FRCA; Jose Lopes Vieira, MD; Leon Villapalos Jorge, MD MSc DIC FRCS (Plast); Annett Volger, MD FRCA; Paul Waddell, DipHE; Josh Wall, MD; Kate Wannap, MD; Patrick Ward, MD FRCA; Ilhan Wardhere, BSc; Andrea Weigert, MD FRCA; Helen Westall, MD; Maria Wilk, BSc; Andrew Williams, MD FRACS (Plast); Jessica Williams, BSc; William Wynn-Jones, MD; Steve Yentis, MD FRCA; Noel Young, MD.

    • Contributors The study was conceived and overseen by MPV. Literature searches were performed by MPV, CLS, MH and RD. The traffic light bioinformatics system was designed and implemented by AH, AB and AM. The clinical study design was by MPV. Data analysis for real-time feedback was performed by MPV and AM. Real-time analytic data application was performed by MPV, MH, SS, LC, AS, RD, CL, MP, AG, JA, TP and RTK. Data analysis was conceived and performed by CLS, and data interpretation was performed by MPV and CLS. Figure 1 was generated by MPV and remaining figures were generated by CLS. The manuscript was written by CLS and revised by MPV, MH, RD, AM and RTK. All authors reviewed and approved the final manuscript.

    • Funding The study received funding support from Chelsea & Westminster NHS Foundation Trust, London, UK, and NHS England.

    • Competing interests None declared.

    • Patient and public involvement Patients and/or the public were involved in the design, or conduct, or reporting, or dissemination plans of this research. Refer to the Methods section for further details.

    • Patient consent for publication Not required.

    • Ethics approval This work was approved by the Chelsea & Westminster NHS Foundation Trust Clinical Governance team and the Data Protection Officer, Head of Information Governance. As we report on routinely collected non-identifiable clinical audit data, no ethical approval was required under the UK policy framework for health and social care.

    • Provenance and peer review Not commissioned; externally peer reviewed.

    • Data availability statement Fully anonymised data will be available post peer-review publication on reasonable request, in accordance with institutional protocols.

    • Addendum Note added in proof. Outcome data are now reported in Vizcaychipi et al, Increase in COVID-19 inpatient survival following detection of Thromboembolic and Cytokine storm risk from the point of admission to hospital by a near real time Traffic-light System (TraCe-Tic). Braz J Infect Dis 2020; S1413-8670(20)30109-4. doi:10.1016/j.bjid.2020.07.010 [online ahead of print]