Background/Purpose:

The overall mortality rate of Systemic Lupus Erythematosus (SLE) has improved significantly over the past 50 years but is still high as compared with the general population. A better knowledge of the causes of death and the related comorbidities is pivotal to improve strategies to prevent death in SLE patients. The aim of the MORTALUP study was to analyze the mortality profile related to SLE in France using a multiple cause-of-death analysis.

Methods:

For the 2000-2009 period, data collected in the French Epidemiological Center for the Medical Causes of Death (CepiDc, Inserm) database and corresponding to death certificates (DC) of adults on which SLE was listed as an underlying or non-underlying cause of death were analyzed. All the DC were collected in a dedicated database after declaration to the Informatics and Liberty National Commission (CNIL). Gender, age, sex-ratio, standardized mortality rates as well as the respective weight and frequency of the various causes of death were assessed.  The age-and sex-adjusted observed/expected death ratio (O/E ratio) was calculated for the main causes of death based on the proportional mortality in the general population between 2000 and 2009 by the same cause provided by the French National Institute for Statistics and Economic Studies (INSEE).

Results:

Overall, 1593 adult SLE patients died during the study period. Sex-ratio was 3.5 (1238 female and 355 male) and mean age at death was 63.5 ± 17.3 years without significant difference between gender. The mean standardized mortality rate was 3.2 per 10⁶ people. For SLE as an underlying cause (n=637, 40%), mean age at death was 61.3 ± 19.3 years and the main non-underlying causes of death were cardiovascular diseases (79.3%), infectious diseases (32.7%) and renal failure (24.8%). Among cardiovascular diseases, heart failure (20.2%) and cerebrovascular diseases (14.7%) were the most frequent.

For SLE as a non-underlying cause of death (n=956, 60%), mean age at death was 65 ± 17.5 years and was significantly higher than in the group where SLE is the underlying cause of death (61.3 ± 19.3 years, p<0.001) years and the most common underlying causes of death were cardiovascular diseases (35.7%), neoplasms (13.9%) and infectious diseases (10.3%). The overall death O/E ratio was > 1 for infectious, cardiovascular diseases and renal failure in both gender, but was <1 for neoplams.

No differences between the Mediterranean area and the rest of France were observed concerning the causes of death. In overseas departments, the standardized mortality rate was higher (10.8 per 10⁶ people) and the mean age of death was earlier (50 years, p< 0.001), but there was no difference regarding the proportion of SLE as underlying/non-underlying cause of death, sex-ratio or causes of death.

Conclusion: To our knowledge, this is the first mortality study using a multiple cause-of-death analysis in SLE in a developed country. At the nation level, cardiovascular diseases are the most important cause of death associated to SLE in France with a significant excess of mortality compared to general population. Cardiovascular interventions should be prioritized in developed country in order to improve SLE survival.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/trends-of-mortality-associated-to-systemic-lupus-erythematosus-at-the-nation-level-a-multiple-cause-of-death-analysis-in-france/