Background/Purpose:  Systemic lupus erythematosus (SLE), is a chronic autoimmune condition. It has the potential to affect any organ system and can be associated with severe morbidity and mortality. Despite improvements in the management of SLE, patients with SLE still have higher mortality rates than the general population. Mortality rates in SLE have been shown to vary between countries and be higher in men. The purpose of this study was to determine the magnitude of risk from all cause and cause-specific mortality in patients with SLE compared to the general population through a meta-analysis of observational studies.

Methods: We searched MEDLINE and EMBASE databases from their inception to October 2011 with an experienced medical librarian. Observational studies that met the following criteria were assessed by two researchers: (a) pre-specified SLE definition; (b) overall and/or cause-specific deaths, cardiovascular disease (CVD), infections, malignancy and renal disease; (c) reported standardized mortality ratio (SMR) and 95% confidence intervals (CI). If data from a single study were reported in more than one article, only the results from the most recent study were included in the meta-analysis. We assessed study quality based on a 12-point scale that included elements of previously published scales for observational studies. We calculated weighted–pooled summary estimates of SMRs (meta-SMR) for all cause and cause-specific mortality using the random effects model, and tested for heterogeneity using I² statistic using STATA.

Results: From 556 abstracts published over the last 65 years, we identified 12 studies (14 cohorts) evaluating the risk of all causeand/or cause-specific mortality, comprising a total of 27,210 patients with SLE, with a total of 4,989 observed deaths. Overall, there was a 300% increased risk of death in patients with SLE when compared to the general population. The jackknife sensitivity analyses showed that all the meta-SMRs remained statistically significant when studies were excluded one at a time, with point estimates ranging from 2.8 to 3.2. Mortality due to malignancy was the only cause-specific entity not increased in SLE (Table). We observed significant heterogeneity among the studies included in our study. However, results from the univariate meta-regression analysis using cohort type, quality assessment and sample type did not explain the heterogeneity.  

Table. Mortality Risk in Patients with SLE compared to the general population

Conclusion: This is the first meta-analysis on SLE mortality using SMRs. Published data indicate that there is a 300% increase in the all-cause mortality in patients with SLE as compared to the general population. In addition, all cause-specific mortality rates, except for malignancy, were also increased with renal disease having the highest mortality risk.