Examining health disparities in systemic lupus erythematosus

Identifying disparities in health among persons of different ethnic or socioeconomic groups, investigating the causes of these disparities, and implementing reme- dies for them have become priorities in national health care research. Among rheumatic diseases, systemic lu- pus erythematosus (SLE) shows marked health dispari- ties that have been the subject of many investigations. Survival rates of patients with SLE have been reported to vary by socioeconomic status (SES) (1-3) and, in some studies, to differ among ethnic groups (4,5). Mor- bidity, as assessed by measures of lupus activity (6,7), permanent organ damage (8-12), functional ability (11), and health status (10,13), has also been found to vary by SES in some, but not all (14,15), studies. In this issue of Arthritis & Rheumatism, Alarcon and colleagues add to this growing literature by report- ing their observations on the development of permanent organ damage in patients enrolled in the LUMINA (lupus in minority populations, nature versus nurture) cohort (16). Over a mean of 5 years, scores on the Systemic Lupus International Collaborating Clinics Damage Index (SDI) increased by 0.4 points among Caucasian and African American patients, but increased by 1 point among Hispanic patients. In multivariate analyses, the most important predictors of an increase in the SDI score were older age and greater lupus activity at study entry, but both Hispanic ethnicity and one measure of SES (household income under the federal poverty level) also predicted greater increases in the SDI score over 5 years. These findings indicate that ethnicity and SES, or factors associated with them, influence the development of organ damage in patients with SLE. Health disparities among persons of different socioeconomic groups are not the result of SES itself, but rather, are due to psychosocial factors that vary with SES and may more directly influence health (17). Ethnic differences in health outcomes also probably have their origin in psychosocial differences, but a contribution from biologic differences must also be considered. Psy- chosocial factors that vary by SES or ethnicity and that might influence health outcomes include health habits, environmental stressors, coping resources, social sup- port, compliance, and access to care, among others. SES and ethnicity are surrogate measures for these psycho- social processes.