5th June 2025

Epidemiology

Incidence and prevalence have been difficult to assess worldwide – studies have mainly focused on white populations in small geographical areas. The incidence in the UK is estimated to be 4.91 per 100,000 person-years, with the highest reported incidence seen in North America (23.2 per 100,000 person-years). Incidence is higher in women compared to men, with reported ratios ranging from 2:1 to 15:1. Peak age of onset is 30-70 for women and 50-70 for men. Prevalence of SLE in the US is estimated to be 72.8 per 100,000 person-years. This prevalence estimate is 9 times higher among women compared to men. There is also a racial and ethnic component, with the highest prevalence seen in African-Americans (230.9 per 100,000 in women, 26.7 per 100,000 in men), followed by Hispanics (120.7 per 100,000 in women, 18 per 100,000 in men), and lowest in white populations (84.7 per 100,000 in women, 8.9 per 100,000 in men). Global data appears to confirm these differences noted in the US data.