Dr. Salmon, director of the Lupus and Antiphospholipid (APS) Center of Excellence at the Hospital for Special Surgery, says, “Lupus is a disease of women in their reproductive years, and pregnancy is always stressful for these patients. There are significant racial disparities in frequency of adverse pregnancy outcomes. Black and Hispanic women with lupus are more likely to have complicated pregnancies. We wanted to dig a bit deeper, and try to untangle the factors that comprise the race/ethnicity variable. Were differences related to genetic factors or driven by socioeconomic status?”
Dr. Salmon and her team utilized data from the multicenter prospective Predictors of Pregnancy Outcome in Systemic Lupus Erythematosus (SLE) and Antiphospholipid Syndrome (PROMISSE) study, and were able to examine outcomes of pregnancies for 408 women with lupus. Patient variables they considered were race and ethnicity, clinical predictors of poor pregnancy outcomes and socioeconomic measures. Adverse pregnancy outcomes included fetal or neonatal death, preterm delivery due to preeclampsia and fetal growth restriction.”
Researchers Puzzled about Similar Circumstances
Dr. Salmon explains, “One thing that has plagued us as we collected pregnancy outcomes over the 11 years of the PROMISSE study was that minority patients fared worse. We found this both fascinating and frustrating, and we couldn’t understand why. They were cared for by the same doctors, they did not have more missed visits than their white counterparts, and they did not have more flares in lupus disease activity.”
To ascertain the nuances involved, Dr. Salmon and her team had to be a bit creative. “We didn’t have personal income data, so we used ZIP codes and U.S. census data to derive median community income. Patients told us their levels of educational attainment.”
“We knew, going into the study, that antiphospholipid antibodies (aPL) were the strongest risk factor for adverse pregnancy outcomes in lupus patients. Interestingly, we found that among all racial/ethnic groups, those with aPL had much worse outcomes, and neither clinical nor socioeconomic factors accounted for this. However, when we looked at SLE patients without aPL, after we adjusted for socioeconomic variables, there were no longer differences in outcome for any minority women compared to white lupus patients. Black women appeared to be at greatest risk for the influence of socioeconomic factors.
“Specifically,” states Dr. Salmon, “White women with lupus with aPL had an adverse pregnancy outcome rate of 29% compared to 11% in white lupus patients without aPL. For black and Hispanic women with or without aPL, the frequency of adverse outcomes was approximately two times greater than that in white women with or without aPL, respectively. It reached 60% in black women with aPL.”
It’s Not Just Access
Every patient in the PROMISSE study was seen monthly by rheumatologists and/or obstetricians with expertise in lupus pregnancy, and compliance with study visits did not vary with race/ethnicity. “It was surprising,” says Dr. Salmon, “to see that the problem was the socioeconomic factors, personal education, median community income and median community education. It is clearly not just access to care that is an issue.”
