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Quantifying the association between ethnicity and COVID-19 mortality: a national cohort study protocol
  1. Hajira Dambha-Miller1,2,
  2. Pui San Tan3,
  3. Defne Saatci3,
  4. Ashley Kieran Clift3,
  5. Francesco Zaccardi4,
  6. Carol Coupland5,
  7. Patrick Locufier6,
  8. Firoza Davies6,
  9. Kamlesh Khunti7,
  10. Simon J Griffin8,
  11. Julia Hippisley-Cox9
  1. 1Primary Care Research Centre, University of Southampton, Southampton, UK
  2. 2MRC Epidemiology Unit, University of Cambridge, Cambridge, UK
  3. 3Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
  4. 4Diabetes Research Centre, University of Leicester, Leicester, UK
  5. 5Division of Primary Care, University of Nottingham, Nottingham, UK
  6. 6PPI Representative, Leicester, UK
  7. 7Department of Health Sciences, University of Leicester, Leicester, UK
  8. 8Institute of Public Health, The Primary Care Unit, Cambridge, UK
  9. 9Nuffield Department of Primary Care Sciences, University of Oxford, Oxford, UK
  1. Correspondence to Dr Hajira Dambha-Miller; hajiradambha{at}


Introduction Recent evidence suggests that ethnic minority groups are disproportionately at increased risk of hospitalisation and death from SARS-CoV-2 infection. Population-based evidence on potential explanatory factors across minority groups and within subgroups is lacking. This study aims to quantify the association between ethnicity and the risk of hospitalisation and mortality due to COVID-19.

Methods and analysis This is a retrospective cohort study of adults registered across a representative and anonymised national primary care database (QResearch) that includes data on 10 million people in England. Sociodemographic, deprivation, clinical and domicile characteristics will be summarised and compared across ethnic subgroups (categorised as per 2011 census). Cox models will be used to calculate HR for hospitalisation and COVID-19 mortality associated with ethnic group. Potential confounding and explanatory factors (such as demographic, socioeconomic and clinical) will be adjusted for within regression models. The percentage contribution of distinct risk factor classes to the excess risks seen in ethnic groups/subgroups will be calculated.

Ethics and dissemination The study has undergone ethics review in accordance with the QResearch agreement (reference OX102). Findings will be disseminated through peer-reviewed manuscripts, presentations at scientific meetings and conferences with national and international stakeholders.

  • COVID-19
  • epidemiology
  • public health

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  • Contributors HD-M led the study conceptualisation, wrote the first draft and revised the protocol. PST, DS and AKC critically revised the manuscript. FZ and CC critically revised the manuscript and contributed to the statistical methods. PL and FD critically revised the manuscript as PPI contributors. KK, SJG and JH-C contributed to study conceptualisation, study design and revised the protocol. The corresponding author attests that all listed authors meet the authorship criteria and that no others meeting the criteria have been omitted. HD-M is the guarantor.

  • Funding This work is funded by an MRC grant (MR/V027778/1). SJG is supported by an MRC Epidemiology Unit programme (MC_UU_12015/4). The University of Cambridge has received salary support in respect of SJG from the NHS in the East of England through the Clinical Academic Reserve. HD-M is a National Institute for Health Research (NIHR)-funded Academic Clinical Lecturer. JH-C receives support from the NHS and the NIHR and various research councils. KK and FZ are supported by the NIHR Applied Research Collaboration East Midlands (ARC EM) and the NIHR Leicester Biomedical Research Centre (BRC). The views and opinions expressed by authors in this publication are those of the authors and do not necessarily reflect those of the UK NIHR or the Department of Health and Social Care.

  • Competing interests JH-C is founder and director of QResearch database, which is a not-for-profit organisation with EMIS (leading commercial supplier of IT for 55% of general practices in the UK). JH-C is co-owner of ClinRisk and was a paid director until June 2019. ClinRisk develops open and closed source software to ensure the reliable and updatable implementation of clinical risk equations within clinical computer systems to help improve patient care, outside the submitted work. KK is national lead for NIHR ARC ethnicity and diversity, Director for the University of Leicester Centre for BME Health, Trustee of the South Asian Health Foundation and member of the Independent SAGE. The authors declare that no support from any organisation and no financial relationships have influenced the submitted work.

  • 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.

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