Population-based Indian Health Service Lupus Registry Finds High Prevalence of Systemic Lupus Erythematosus Among AI/AN Women
Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by multiple organ system involvement (especially kidney failure) and widely variable clinical presentations. Prevalence estimates vary widely with much higher prevalence in women and in non-white ethnic groups. In order to better understand the magnitude and impact of SLE, the Centers for Disease Control and Prevention have funded five lupus registries including the Indian Health Service (IHS) Lupus Registry. The project objectives are to determine how many cases of lupus exist (prevalence) and how many new cases occur each year (incidence).
METHODS:
While the goal of the IHS Lupus Registry is to provide estimates of SLE prevalence and incidence generalizable to the entire US American Indian/Alaska Native (AI/AN) population, data collection was limited to AI/AN people who were active users of IHS clinical services in the Alaska (n = 117,964), Oklahoma (n = 23,641), and Phoenix (n = 70,311) Areas from 2007 through 2009. Cases were identified as individuals meeting 4 or more of the 11 American College of Rheumatology SLE classification criteria.
RESULTS:
Age-adjusted SLE prevalence among AI/AN people in 2007 were similar in Alaska (149 per 100,000; 95% CI: 124 – 177) and Oklahoma (138 per 100,000; 95% CI: 93 – 200) and significantly lower than in Phoenix (248 per 100,000, 95% CI: 204 – 297). Among AI/AN women age-adjusted prevalence ranged from 224 per 100,000 (95% CI: 183 – 271) in Alaska and 186 per 100,000 (95% CI: 120 – 277) in Oklahoma to 385 per 100,000 (95% CI: 316 – 464) in Phoenix.
CONCLUSIONS:
SLE prevalence estimates for three IHS regions are higher than those previously reported for US whites and similar to those reported for other non-white ethnic groups. SLE prevalence among AI/AN people varies by region.