Despite improving trends in mortality, death rates from systemic lupus erythematosus (lupus) remain high compared with those in the general population, and disparities persist between subpopulations and geographic regions, according to a report in the Annals of Internal Medicine.
In addition, underreporting of lupus on death certificates may have resulted in underestimates of mortality rates, stated researchers from the David Geffen School of Medicine at the University of California Los Angeles.
Lupus is a chronic autoimmune disease with limited treatment options. In the 1950s, 5- and 10-year survival rates were less than 50%, but those rates jumped to more than 90% in the 1980s.
The influence of more recent diagnostic and therapeutic developments on lupus mortality in the general population of the U.S. is unknown. Previous studies of lupus mortality were based primarily on deaths in patient cohorts, which do not capture changes in lupus incidence over time, and do not reflect the true burden and trends of lupus mortality in the general population.
The investigators used a national mortality database and census data to identify temporal trends and demographic and regional differences in lupus mortality in the U.S. over 40-plus years (1968 through 2013).
They found that the reduction in mortality attributed to lupus was less than the reduction in non-lupus mortality, and the ratio of lupus to non-lupus mortality was about 35% higher in 2013 than in 1968. After an initial decrease between 1968 and 1975, lupus mortality increased annually for 24 years, followed by a sustained decrease for 14 years starting in 1999. Changes in lupus incidence over time could partially explain the changing trends; however, significant disparities in lupus mortality among subpopulations were observed.
Mortality rates remained higher among older persons, females, blacks, and Hispanics, as well as in patients who resided in geographic regions in the West and the South. Most interestingly, according to the authors, people of the same race/ethnicity had differences in lupus mortality, depending on where they lived. While those living in the South had the highest lupus mortality, non-whites had the highest lupus mortality in the West.
The study authors stressed that it is encouraging that lupus mortality began to decrease in 1999, and that the decrease has been sustained for 14 years, until the end of the study period. They suggested that additional research could help identify any potentially modifiable risk factors that might inform targeted research and public health programs to address the disparities in lupus mortality rates.
A version of this article first appeared on RheumNow, a news, information and commentary site dedicated to the field of rheumatology. Register to receive their free rheumatology newsletter.