Background/Purpose:  The epidemiology of SLE has a complex gendered aspect, characterized by marked differences between the sexes in terms of the incidence, prevalence, and clinical manifestations. Males are reportedly less likely to be afflicted with SLE and women of childbearing age are disproportionately impacted. Females with SLE have more frequent exacerbations in general, but male patients appear to have significantly greater multi-systemic damage accrual and disease severity. Monitoring the fatal outcomes of SLE and frequency of common patterns of causes of death may offer insight into emerging health issues affecting contemporary SLE patients and can suggest the direction of future epidemiological investigations, particularly through a sex-based lens. This study provides a nuanced understanding of causes of deaths, related co-morbidities, and mortality differentials between males and females with SLE.

Methods: A cross-sectional study was performed on ~2.7 million death records from 2014 using the National Center for Health Statistics Multiple Cause of Death (MCOD) database, a population-based electronic medical recording of all death certificates issued in the United States. ICD-10 codes were isolated from the MCOD files and classified according to the Clinical Classifications Software (CCS), a well-developed categorization scheme that collapses ICD-10 codes into 260 clinically relevant categories. We compared sex-stratified demographic characteristics and the most frequently cited conditions in decedents with and without SLE. Relative risks quantified the risk of dying with the most frequently cited conditions among decedents aged ≤50 years comparing those with and without SLE to estimate the burden of premature deaths in this population.

Results:  In 2014, there were 2,036 decedents with SLE in the United States. Females and Blacks comprised 86.2% and 30.7% of all SLE-related deaths, respectively. Female decedents with SLE died, on average, 22 years earlier (median age at death was 59 years) than those without SLE. Male decedents with SLE died 12 years earlier (median age at death was 61 years) than non-SLE males. Top causes of death in females and males with SLE were heart disease, diabetes, and hypertension. Among decedents aged ≤50 years, males with SLE had higher co-occurrence of coagulation and hemorrhagic disorders and chronic renal failure compared with those without SLE (RR: 16.69, 95% CI: 10.50-27.44; and RR: 5.76, 95% CI: 2.76-12.00, respectively). These co-morbid conditions were also important contributory causes of premature mortality among women, but to a lesser degree (RR: 4.98, 95% CI: 3.69-6.70; and RR: 8.55, 95% CI: 6.89-10.61, respectively).

Conclusion : Our findings identify important clinically relevant comorbidities that need to be considered more carefully in the course of patients’ clinical management and the natural history of SLE disease.