Causes of Death Among Individuals With Systemic Lupus Erythematosus by Race and Ethnicity: A Population-Based Study

Objective: Non-White populations are at higher risk of developing systemic lupus erythematosus (SLE) and have more severe outcomes, including mortality. The present study was undertaken to examine how specific causes of death vary by race and ethnicity, including Asian and Hispanic individuals.

Methods: The California Lupus Surveillance Project included SLE cases identified among residents of San Francisco County, CA during January 1, 2007 to December 31, 2009. Cases were matched to the National Death Index over a 10-year period. Logistic regression examined age-adjusted differences in causes of death by race, ethnicity, and sex. Age-standardized mortality ratios between individuals with SLE and the corresponding general population were calculated for the leading cause of death, and observed versus expected deaths were estimated.

Results: The study included 812 individuals of White (38%), Asian (36%), Black (20%), and mixed/other/unknown (5%) race; 15% identified as Hispanic. One hundred thirty-five deaths were recorded, with a mean ± SD age at death of 62.2 ± 15.6 years. Cardiovascular disease (CVD) was the leading cause of death overall (33%), and across all racial and ethnic groups, followed by rheumatic disease (18%) and hematologic/oncologic conditions (18%). CVD as the underlying cause of death was 3.63 times higher among SLE cases than in the general population. CVD deaths for those with SLE were nearly 4 and 6 times higher for Asian and Hispanic individuals with SLE, respectively, compared to the general population.

Conclusion: Individuals with SLE experience a disproportionate burden of CVD mortality compared to the general population, which is magnified for Asian and Hispanic groups.