CORYLUS UK: A retrospective observational cohort study of the impact of COVID-19 on systemic lupus erythematosus patients in England using data from linked primary and secondary care databases

Date of Approval
Application Number
Technical Summary

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterised by autoantibodies, systemic inflammation and lymphopenia. There is no cure for SLE, and treatment depends on severity, including non-steroidal anti-inflammatories (NSAIDs), corticosteroids, immunosuppressants, and antimalarial agents such as chloroquine or hydroxychloroquine. Whilst corticosteroids are rapidly effective for suppressing flares, long term use has considerable side-effects[1].
The COVID-19 pandemic has had an enormous impact on patient care for those living with chronic diseases, including lower healthcare-seeking behaviour, and shielding for severely immunocompromised patients to lower their risk of exposure to the virus. However, with similar treatment regimens for SLE and COVID-19 considered, it is unknown whether SLE patients are at a greater or lower risk of severe COVID-19 infections.
This descriptive retrospective observational cohort study aims to investigate the impact that the COVID-19 pandemic has had upon SLE patients, stratified according to the severity of their autoimmune disease. The demographic and clinical profiles of SLE patients will be described, stratified by severity of SLE and COVID-19 status. SLE severity will be determined using an algorithm that incorporates comorbid conditions and medications prescribed within the twelve months prior to the study period. Among SLE patients who are diagnosed with COVID-19 within the study period, metrics for mortality, admissions and lengths of stay will be calculated, stratified by severity of COVID-19.
This description of healthcare resource use will provide insight into whether the incidence rates of COVID-19 amongst SLE patients are higher or lower than published incidences amongst the general population, and whether patients with more severe SLE have experienced worse COVID-19 specific outcomes and mortality rates. This information can be used to inform policy and improve patient management for SLE patients who may be exposed to COVID-19.

Health Outcomes to be Measured

The number of patients in each SLE sub-cohort; The total number and cumulative incidence of COVID-19 infections per calendar month amongst these sub-cohorts, stratified by COVID-19 severity; Demographic profiles for each sub-cohort (Mean, median, minimum, and maximum age at SLE diagnosis, gender, ethnicity, BMI, total time in cohort, mean and median follow-up time, Charlson Co-morbidity Score); Clinical profiles of SLE patients at entry into the observation period (Recorded prescriptions in primary care for corticosteroids, other steroids, immunosuppressive agents: azathioprine, cyclosporin, methotrexate, mycophenelate, and hydroxychloroquine or other antimalarial; number and percentage of patients with a record in HES relating to high cost biologics, Number and percentage of patients with comorbidities of interest (diabetes, hypertension, history of pneumonia, arterial/venous thrombosis, haemolytic anaemia, end-stage renal disease or dialysis, nephritis, history of myocardial infarction, history of stroke, obesity, hypercholesterolemia); mean, median, minimum, and maximum age of SLE patients at COVID-19 diagnosis; acute case fatality rate of COVID-19; COVID-specific admission rate and lengths of stay; all-cause admission rates and lengths of stay between COVID-19 severity groups, including those without a COVID-19 diagnosis; COVID-19 clinical outcomes and therapies in secondary care (respiratory distress, oxygen therapy, mechanical ventilation, organ failure, pneumonia


Jay Were - Chief Investigator - Health iQ
Shea O'Connell - Corresponding Applicant - Health iQ
Archie Farrer - Collaborator - Health iQ
Boglarka Kovacs - Collaborator - Health iQ
Gulsah Akin Unal - Collaborator - Health iQ
Judith Ruzangi - Collaborator - Health iQ
Mico Hamlyn - Collaborator - Health iQ


HES Accident and Emergency;HES Admitted Patient Care;HES Outpatient;ONS Death Registration Data