To determine whether socioeconomic status assessed by education is associated with disease activity and the risk of organ damage in systemic lupus erythematosus (SLE).
Data from the 1000 Canadian Faces of Lupus, a multicenter database of adult SLE patients, was used to compare education as either low (did not complete high school) or high (completed high school or further) for disease activity and damage. Education was also studied as a continuous variable. The relationships between education and SLE outcomes (any organ damage defined as a Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index [SDI] score ≥1, serious organ damage [SDI score ≥3], and end-stage renal disease) were evaluated using logistic regression analyses adjusted for age, sex, race/ethnicity, and disease duration.
A total of 562 SLE patients met inclusion criteria (mean age 47 years, 91% female, and mean disease duration of 10 years); 81% had high education. The low education group was twice as likely to be work disabled (30%; P < 0.0001); they had higher disease activity and reduced renal function. Linear regression analysis revealed that low education was significantly associated with higher disease activity at enrollment into the 1000 Canadian Faces of Lupus database, after adjustment for age (at entry and at diagnosis), race/ethnicity, and sex (B 1.255 + 0.507 [SE], β = 0.115, P = 0.014). In our adjusted logistic regression models we were unable to demonstrate significant associations between education and SLE damage. Results did not change when varying the education variable.
In this cohort, low education was associated cross-sectionally with higher disease activity and work disability, but not damage.