The impact of race and ethnicity on disease severity in systemic lupus erythematosus.

OBJECTIVES: Systemic lupus erythematosus (SLE) can result in comorbidities and high disease severity. The aim of this study was to evaluate the effects of age, sex, race, ethnicity, cost of hospitalization, length of stay, and payor source on SLE disease severity scores.
DESIGN: Epidemiological study.
SETTING: Hospital discharge data were obtained from the DFW Hospital Council (DFWHC), for 65,535 patients hospitalized in the North Texas Dallas-Fort Worth (DFW) Metropolitan Statistical Area (MSA) from 1999-2005 with at least one autoimmune disease. PATIENTS: Of the 65,535 autoimmune patients, 14,829 patients had SLE as a diagnosis. The sample was assessed for disease severity according to the SLE comorbidity Index. MAIN OUTCOME: Disease severity, SLE comorbidities.
RESULTS: SLE patients were younger and more than five times more likely to have multiple autoimmune diseases. More than one third of Hispanic patients were on Medicaid or self-pay and more likely to have higher disease severity. Race (Caucasian), sex (female), and payor source (PPO/POS) predicted lower disease severity scores. SLE was predictive of eight of the fourteen SLE-CI diseases, with greatest effects observed for nephritis (OR = 3.30, P < .0001), chronic renal failure (OR = 3.36, P < .0001), pericarditis (OR = 3.2, P < .0001), and pleuritis (OR = 2.06, P < .0001). Non-Caucasian patients were more likely to have chronic renal failure, nephritis, congestive heart failure, pericarditis and pleuritis.
CONCLUSIONS: The comorbidities that exist in SLE vary according to ethnicity. It is paramount for physicians to be cognizant of these disparities and make appropriate referrals.