Characteristics and outcomes of clinically diagnosed RT-PCR swab negative COVID-19: a retrospective cohort study

Paul Middleton, Pablo N. Perez-Guzman, Alexandra Cheng, Naveenta Kumar, Mara D. Kont, Anna Daunt, Sujit Mukherjee, Graham Cooke, Timothy B. Hallett, Katharina Hauck, Peter J. White, Mark R. Thursz, Shevanthi Nayagam*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


Patients with strong clinical features of COVID-19 with negative real time polymerase chain reaction (RT-PCR) SARS-CoV-2 testing are not currently included in official statistics. The scale, characteristics and clinical relevance of this group are not well described. We performed a retrospective cohort study in two large London hospitals to characterize the demographic, clinical, and hospitalization outcome characteristics of swab-negative clinical COVID-19 patients. We found 1 in 5 patients with a negative swab and clinical suspicion of COVID-19 received a clinical diagnosis of COVID-19 within clinical documentation, discharge summary or death certificate. We compared this group to a similar swab positive cohort and found similar demographic composition, symptomology and laboratory findings. Swab-negative clinical COVID-19 patients had better outcomes, with shorter length of hospital stay, reduced need for > 60% supplementary oxygen and reduced mortality. Patients with strong clinical features of COVID-19 that are swab-negative are a common clinical challenge. Health systems must recognize and plan for the management of swab-negative patients in their COVID-19 clinical management, infection control policies and epidemiological assessments.

Original languageEnglish
Article number2455
Number of pages7
JournalScientific Reports
Issue number1
Publication statusPublished - 28 Jan 2021

Bibliographical note

Funding Information:
This work was supported by Medical Research Council Centre for Global Infectious Disease Analysis and the NIHR HPRU in Modelling and Health Economics. SN, TBH, KH, PJW and PP were supported by the MRC Centre for Global Infectious Disease Analysis (MR/R015600/1); this award is jointly funded by the UK Medical Research Council (MRC) and the UK Foreign, Commonwealth & Development Office (FCDO) under the MRC/FCDO Concordat agreement and is also part of the EDCTP2 program supported by the European Union (EU). PJW is supported by the NIHR HPRU in Modelling and Health Economics, a partnership between Public Health England, Imperial College London and LSHTM (grant code NIHR200908). The authors would also like to acknowledge the support of the Imperial BRC Centre and J-IDEA. The authors would like to thank all patients and staff at Imperial College Healthcare NHS Trust. Role of the Funder/Sponsor: The funding organizations had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication. Disclaimer: The views expressed are those of the authors and not necessarily those of the United Kingdom (UK) Department of Health and Social Care, EU, FCDO, MRC, National Health Service, NIHR, or PHE.

Publisher Copyright:
© 2021, The Author(s).


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