Mortality studies in systemic lupus erythematosus. Results from a single center. I. Causes of death

Objective. To study the causes of death in patients with SLE, followed prospectively in a single center. Methods. The study population comprised 665 patients with systemic lupus erythematosus (SLE). Causes of death were determined by review of hospital files, autopsy reports, and death certificates. Nonparametric lifetable models were used to calculate Kaplan-Meier estimates of survival probabilities. Results. One hundred and twenty-four patients (18.6%) had died. The primary causes of death were active SLE in 20 (16%), infection in 40 (32%), acute vascular event in 19 (15.4%), sudden death in 10 (8.1%), organ failure in 6 (4.8%), malignancy in 8 (6.5%), others in 8 (6.5%), and unknown in 13 (10.5%). Death as a result of active SLE was more common in patients who died within 5 years of diagnosis compared to those dying after 5 years (p = 0.021), and deaths due to vascular events and end organ failure not related to active lupus were more frequent in the late death group (p = 0.028). The overall 5, 10, 15, and 20 year survival rates were 93, 85, 79, and 68%, respectively. Patients with SLE had a 4.92 fold increased risk for death compared with the general population. Conclusion. Survival rates continue to improve in SLE but causes of mortality vary at different stages.