46-Year Trends in Systemic Lupus Erythematosus Mortality in the United States, 1968 to 2013: A Nationwide Population-Based Study.

BACKGROUND

No large population-based studies have been done on systemic lupus erythematosus (SLE) mortality trends in the United States.

OBJECTIVE

To identify secular trends and population characteristics associated with SLE mortality.

DESIGN

Population-based study using a national mortality database and census data.

SETTING

United States.

PARTICIPANTS

All U.S. residents, 1968 through 2013.

MEASUREMENTS

Joinpoint trend analysis of annual age-standardized mortality rates (ASMRs) for SLE and non-SLE causes by sex, race/ethnicity, and geographic region; multiple logistic regression analysis to determine independent associations of demographic variables and period with SLE mortality.

RESULTS

There were 50 249 SLE deaths and 100 851 288 non-SLE deaths from 1968 through 2013. Over this period, the SLE ASMR decreased less than the non-SLE ASMR, with a 34.6% cumulative increase in the ratio of the former to the latter. The non-SLE ASMR decreased every year starting in 1968, whereas the SLE ASMR decreased between 1968 and 1975, increased between 1975 and 1999, and decreased thereafter. Similar patterns were seen in both sexes, among black persons, and in the South. However, statistically significant increases in the SLE ASMR did not occur among white persons over the 46-year period. Females, black persons, and residents of the South had higher SLE ASMRs and larger cumulative increases in the ratio of the SLE to the non-SLE ASMR (31.4%, 62.5%, and 58.6%, respectively) than males, other racial/ethnic groups, and residents of other regions, respectively. Multiple logistic regression showed independent associations of sex, race, and region with SLE mortality risk and revealed significant racial/ethnic differences in associations of SLE mortality with sex and region.

LIMITATIONS

Underreporting of SLE on death certificates may have resulted in underestimates of SLE ASMRs. Accuracy of coding on death certificates is difficult to ascertain.

CONCLUSION

Rates of SLE mortality have decreased since 1968 but remain high relative to non-SLE mortality, and significant sex, racial, and regional disparities persist.

PRIMARY FUNDING SOURCE

None.