Background Mortality rates for lupus and lupus nephritis significantly vary by race/ethnicity and geographic region. Here, we examine place of death as an indirect indicator of disease outcome and accessibility to healthcare on a national scale for lupus nephritis.

Methods We used the Center for Disease Control and Prevention’s WONDER database, which compiles mortality data from all 50 states and the District of Columbia. We obtained data on lupus nephritis deaths by place of death, grouped the occurrence of deaths by medical facility (emergency department, inpatient, and outpatient) and non-medical facility (home, hospice and nursing home). We further stratified this data by 4 race/ethnic groups, non-Hispanic (NH) white, NH-black, NH-others (Asian/Pacific Islander and American Indian/Alaskan Native), and Hispanic/Latinos. We also classified deaths by the four census regions to examine racial and regional variations in mortality by place of death using the Fisher’s exact test. Furthermore, we examined temporal differences in mortality by place of death by comparing mortality in 1999–2009 to mortality in 2010–2020 using the Fisher’s exact test.

Results Of 9,400 deaths attributed to lupus nephritis from 1999 through 2020, 76% occurred at medical facilities and 24% at home/hospice/nursing home. The proportions of death at medical facilities have decreased over the 22-year-period: 81–82% in the first five years to 66–73% in the last five years (p<0.05). Of lupus nephritis decedents at medical facilities, 42% were NH-black persons, 36% NH-white, 16% Hispanic, and 7% NH-others. When compared to NH-white persons, NH black, NH-others were significantly more likely to die in a medical facility with an odds ratio of 2.523 (p <0.0001), 2.268 (p <0.0001), and 2.322 (p <0.0001), respectively. Over the 22-year period, medical facility deaths have significantly decreased for NH-white (40- 44% in the first 5 years to 23–34% in the last 5 years), whereas it has increased for all non-white subpopulations. Across geographic regions, most deaths (43.7%) occurred in the South, followed by West (25.0%), Midwest (16.8%) and Northeast (14.5%). Lupus nephritis deaths at medical facilities significantly decreased across all regions, though there are substantial variations by race/ethnicity. Medical facility deaths significantly decreased for NH-white persons in all regions but the West; for Hispanics it only decreased in the West; for NH-black persons it decreased in all regions but the Northeast; and for NH-others it decreased in the Midwest and West.

Conclusions There are clear disparities in mortality by place of death among racial/ethnic groups: more non- white subpopulations die of lupus nephritis at medical facilities than white individuals and this disparity has worsened over the past 22 years. The regional variations in lupus nephritis deaths, overall and by race/ethnicity, may reflect regional variations in accessibility to health care and disease severity. Further research should examine lupus nephritis patient data from medical centers across the United States to specifically identify factors that predispose certain groups to poorer disease outcomes.