Survival rate among Thai systemic lupus erythematosus patients in the era of aggressive treatment

Abstract

Background: The major cause of death in systemic lupus erythematosus (SLE) is due to the disease activity itself or infection. It is uncertain whether the treatment approach during the last decade prolonged survival in SLE.

Objective: Our objective was to identify the causes of death and the factors predictive of mortality and to calculate the survival rate among SLE patients.

Method: We conducted a retrospective study of SLE patients followed up at Srinagarind Hospital, Khon Kaen University, Thailand, between January 1, 1996 and August 31, 2005. Cox regression analysis was used to estimate the probability of survival and assessing factors associated with death. The medical records of 749 SLE patients were reviewed; 66 patients died during the follow-up period.

Results: The mortality rate was 1.2 per 100 person-years. The 5- and 10-year survival rate among our SLE patients was 93% and 87%, respectively. The mean age at death was 34.08 ± 11.75 years and the median disease duration was 48 (1-336) months. One-third of the cases were referred from a local hospital more than 1 month after onset and were associated with a significantly higher risk of mortality than cases referred earlier (P = 0.047). The most common causes of death were opportunistic pulmonary infections and neuropsychiatric lupus. Factors predictive of mortality included: (i) major organ flare more than four times per year; (ii) age at onset > 50 years; (iii) high-dose steroid use and/or immunosuppressive therapy at onset and within 2 weeks prior to death; and (iv) concomitant diabetes mellitus. Protective against mortality was antimalarial use.