Education level and mortality in systemic lupus erythematosus (SLE): Evidence of underascertainment of deaths due to SLE in ethnic minorities with low education levels

Abstract

To determine if socioeconomic status, as measured by education level, is associated with mortality due to systemic lupus erythematosus (SLE), and to determine if these associations differ among ethnic groups. Sex- and race-specific mortality rates due to SLE by education level were computed for persons age 25-64 years using US Multiple Causes of Death data from 1994 to 1997. SLE-specific mortality rates were compared with all-cause mortality rates in 1997 to determine if the association between education level and mortality in SLE was similar to that in other causes of death. Among whites, the risk of death due to SLE was significantly higher among those with lower levels of education, and the risk gradient closely paralleled the 1997 all-cause mortality risks by education level. However, in African American women and men and Asian/Pacific Islander women, the risk of death due to SLE was lower among those with lower education levels, contrary to the associations between education level and all-cause mortality in these groups. Comparing the distribution of education levels among deaths due to SLE and all deaths in 1997, persons with lower education levels were underrepresented among deaths due to SLE in African Americans and Asian/Pacific Islanders. Among whites, higher education levels are associated with lower mortality due to SLE. These associations were not present in ethnic minorities, likely due to underascertainment of deaths due to SLE in less-well educated persons. This underascertainment may be due to underreporting of SLE on death certificates, but may also represent underdiagnosis of SLE in ethnic minorities with low education levels.