Impact of SARS-CoV-2 infection on patients with systemic lupus erythematosus in England prior to vaccination: a retrospective observational cohort study

Abstract

Objectives: Determine the prevaccination healthcare impact of COVID-19 in patients with systemic lupus erythematosus (SLE) in England.

Design: Retrospective cohort study of adult patients with SLE from 1 May to 31 October 2020.

Setting: Clinical Practice Research Datalink (CPRD) Aurum and Hospital Episode Statistics (HES) databases from general practitioners across England combining primary care and other health-related data.

Participants: Overall, 6145 adults with confirmed SLE diagnosis ≥1 year prior to 1 May 2020 were included. Most patients were women (91.0%), white (67.1%), and diagnosed with SLE at age <50 (70.8%). Patients were excluded if they had a COVID-19 diagnosis before 1 May 2020.

Primary and secondary outcome measures: Demographics and clinical characteristics were compared. COVID-19 severity was determined by patient care required and procedure/diagnosis codes. COVID-19 cumulative incidence, hospitalisation rates, lengths of stay and mortality rates were determined and stratified by SLE and COVID-19 severity.

Results: Of 6145 patients, 3927 had mild, 1288 moderate and 930 severe SLE at baseline. The majority of patients with moderate to severe SLE were on oral corticosteroids and antimalarial treatments. Overall, 54/6145 (0.88%) patients with SLE acquired and were diagnosed with COVID-19, with 45 classified as mild, 6 moderate and 3 severe COVID-19. Cumulative incidence was higher in patients with severe SLE (1.4%) compared with patients classified as mild (0.8%) or moderate (0.8%). Ten COVID-19-specific hospital admissions occurred (n=6 moderate; n=4 severe). Regardless of COVID-19 status, hospital admission rates and length of stay increased with SLE severity. Of 54 patients with SLE diagnosed with COVID-19, 1 (1.9%) COVID-19-related death was recorded in a patient with both severe SLE and severe COVID-19.

Conclusions: SLE severity did not appear to impact COVID-19 outcomes in this study. The COVID-19 pandemic is evolving and follow-up studies are needed to understand the relationship between COVID-19 and SLE.

Keywords: COVID-19; GENERAL MEDICINE (see Internal Medicine); HEALTH ECONOMICS; INFECTIOUS DISEASES; PUBLIC HEALTH; RHEUMATOLOGY.

Figure 1

Schematic of study design and criteria for patient selection. Patients were stratified by SLE severity within the 12-month baseline period (May 2019 to May 2020). All patients were required to have valid data to be considered for evaluation in the follow-up period and to be considered at-risk of COVID-19 within the study. CPRD, Clinical Practice Research Datalink; HES, Hospital Episode Statistics; ID, index date; SLE, systemic lupus erythematosus.

Figure 2

Cumulative incidence of COVID-19 diagnoses over the 6-month evaluation period according to SLE severity. No comparative inferential statistical analyses were performed; cumulative incidence of COVID-19 diagnoses across SLE subgroups was evaluated with descriptive statistics only. SLE, systemic lupus erythematosus.