The incidence, mortality and complications of systemic lupus erythematosus: a population-level cohort study from 2012...

Ethnicity-related inequalities in the epidemiology of systemic lupus erythematosus (SLE) have been consistently described, yet robust population-level data remain limited. We aimed to characterize the incidence, all-cause mortality and complications of SLE in a contemporary, ethnically diverse, nationwide cohort.

We conducted a population-level study using the Clinical Practice Research Datalink in England. Individuals aged ≥18 years with new SLE diagnoses between 2012 and 2023 were included. Controls were selected in a 4:1 ratio and matched on age, sex and primary care practice. Risk of death and complications were estimated using flexible parametric and competing-risk models, respectively.

The cohort consisted of 4937 incident SLE diagnoses (87.9% female; median age 47 years). The incidence of SLE declined over the study period across all ethnicities. Compared with controls (n = 19 707), patients with SLE had significantly higher mortality risk [hazard ratio (HR) 2.06; 95% CI: 1.84, 2.32] and elevated risk of all studied complications except solid cancers. SLE incidence was highest among people of Black ethnic background, with the greatest rates observed in Black Caribbean individuals (11.07 per 100 000 person-years in 2023; 95% CI: 6.05, 18.58). Compared with White individuals with SLE, Black individuals had significantly higher mortality (HR 1.64; 95% CI: 1.05, 2.55) and increased risks of diabetes, thrombosis, myocarditis/pericarditis and interstitial lung disease.

Despite declining incidence, mortality for people with SLE was twice that of controls in this large contemporaneous incident cohort. Ethnicity-based inequalities were observed, with elevated mortality and morbidity risk in Black ethnic groups with SLE compared with White ethnic groups.