Risk factors for mortality in systemic lupus erythematosus patients: Analysis of adult and pediatric cohorts in Taiwan

Background: Overall survival of systemic lupus erythematosus (SLE) patients significantly increased in recent decades, however, the relative risk of mortality is still high. Long-term survival outcome of pediatric SLE remains unclear. This study aims to explore the long-term survival rate and its predictors in patients with systemic lupus erythematosus (SLE).

Methods: A retrospective, hospital-based cohort study was performed between 2004 and 2018 in a tertiary referral medical center in Taiwan. Data on comorbidities, medications, and causes of admission were collected for risk factor analysis using time-dependent multivariate Cox proportional hazards models.

Results: A total of 2392 adults and 115 pediatric SLE patients were enrolled (female, n = 2157 and 95, respectively). The 10-year survival rates were 93.2%, 90.2%, 98.9%, and 100% in adult women, adult men, girls, and boys with SLE, respectively. The overall mortality rate was 2.09 case/100 patient-years (PY) for male SLE and 1.39 case/100 PY for female SLE patients. Male SLE patients did not have a statistically significantly higher mortality rate than female SLE patients in each age stratification. Infectious disease (n = 119), heart failure (n = 21), and cerebrovascular accident (n = 14) were the leading causes of death in adult SLE patients. Advanced age (hazard ratio [HR]: 1.04, 95% confidence interval [CI]: 1.03-1.05), treatment with mean dosage of systemic glucocorticoid equivalent to >10 mg/d of prednisolone (HR: 1.71, 95% CI: 1.14-2.57), comorbidities with malignancy (HR: 1.94, 95% CI: 1.22-3.09), chronic kidney disease (HR: 1.86, 95% CI: 1.25-2.77), hypertension (HR: 1.42, 95% CI: 1.01-1.98), and admission due to bacterial pneumonia (HR: 1.92, 95% CI: 1.12-3.31) and sepsis (HR: 2.78, 95% CI: 1.51-5.13) were independent risk factors for mortality in SLE patients.

Conclusion: SLE patients with advanced age, malignancy, chronic kidney disease, hypertension, treated with a higher average dosage of glucocorticoids, and admission due to bacterial pneumonia and sepsis have an increased risk of mortality.