COVID-19 clinical risk assessment for guiding patient placement and diagnostic testing strategy on admission to hospital

Introduction: Without universal access to point-of-care SARS-CoV-2 testing, many hospitals rely on clinical judgement alone for identifying cases of COVID-19 early.Methods: Cambridge University Hospitals NHS Foundation Trust introduced a traffic lights clinical judgement aid to the COVID-19 admissions unit in mid-March 2020. Ability to accurately predict COVID-19 was audited retrospectively across different stages of the epidemic. Results:  One SARS-CoV-2 PCR positive patient (1/41, 2%) was misallocated to a ‘green’ (non-COVID-19) area during the first period of observation, and no patients (0/32, 0%) were mislabelled ‘green’ during the second period. 33 of 62 (53%) labelled ‘red’ (high risk) tested SARS-CoV-2 PCR positive during the first period, while 5 of 22 (23%) ‘red’ patients were PCR positive in the second. Conclusion: COVID-19 clinical risk stratification on initial assessment effectively identifies non-COVID-19 patients. However, diagnosing COVID-19 is challenging and risk of overcalling COVID-19 should be recognised, especially when background incidence is low. Key words: SARS-CoV-2, COVID-19, Coronavirus, Triage, Diagnostics, Infection Control