Overall and cause-specific mortality in patients with systemic lupus erythematosus: a meta-analysis of observational studies

Abstract

Objective: To determine the magnitude of risk from all-cause and cause-specific mortality in patients with systemic lupus erythematosus (SLE) compared to the general population through a meta-analysis of observational studies.

Methods: We searched the Medline and Embase databases from their inception to October 2011. Observational studies that met the following criteria were assessed: 1) a prespecified SLE definition; 2) overall and/or cause-specific deaths, including cardiovascular disease (CVD), infections, malignancy, and renal disease; and 3) reported standardized mortality ratios (SMRs) and 95% confidence intervals (95% CIs). We calculated weighted-pooled summary estimates of SMRs (meta-SMRs) for all-cause and cause-specific mortality using the random-effects model and tested for heterogeneity using the I(2) statistic by using Stata/IC statistical software.

Results: We identified 12 studies comprising 27,123 patients with SLE (4,993 observed deaths) that met the inclusion criteria. Overall, there was a 3-fold increased risk of death in patients with SLE (meta-SMR 2.98, 95% CI 2.32-3.83) when compared with the general population. The risks of death due to CVD (meta-SMR 2.72, 95% CI 1.83-4.04), infection (meta-SMR 4.98, 95% CI 3.92-6.32), and renal disease (SMR 7.90, 95% CI 5.50-11.00) were significantly increased. Mortality due to malignancy was the only cause-specific entity not increased in SLE (meta-SMR 1.19, 95% CI 0.89-1.59).

Conclusion: The published data indicated a 3-fold increase in all-cause mortality in patients with SLE compared to the general population. Additionally, all cause-specific mortality rates were increased except for malignancy, with renal disease having the highest mortality risk.