Good survival rates in systemic lupus erythematosus in southern Sweden, while the mortality rate remains increased compared with the population.

OBJECTIVE: To ascertain the mortality rate and causes of death in patients with systemic lupus erythematosus (SLE) within a defined region in southern Sweden during the time period 1981-2014 and determine whether these have changed over time. METHODS: In 1981, a prospective observation study of patients with SLE was initiated in southern Sweden. All incident SLE patients within a defined geographic area were identified using previously validated methods including diagnosis and immunology registers. Patients with a confirmed SLE diagnosis were then followed prospectively at the Department of Rheumatology in Lund. Clinical data was collected at regular visits. Patients were recruited from 1981 to 2006 and followed until 2014. The patient cohort was split into two groups based on the year of diagnosis to determine secular trends. Causes of death were retrieved from medical records and from the cause of death registry at The National Board of Health and Welfare in Sweden. RESULTS: In all, 175 patients were diagnosed with SLE during the study period. A total of 60 deaths occurred during a total of 3053 years of follow-up. In the first half of the study inclusion period 46 patients died, compared with 14 in the latter. The majority of patients (51.7%) died of cardiovascular disease. Infections caused 15% of the deaths and malignancy was the cause of death in 13.3% of patients. SLE was the main cause of death for 6.7% of the patients and a contributing factor for half of the patients. Standardized mortality ratio was increased in patients by a factor of 2.5 compared with the general population. Deaths occurred at an even rate throughout the whole observation period. No significant difference in standardized mortality ratio was observed between genders but was increased in older female patients. Furthermore, secular mortality trends were not identified. CONCLUSIONS: In this long-term epidemiologic follow-up study of incident SLE, we report a substantially raised mortality rate amongst SLE patients compared with the general population. The mortality rates have not changed significantly during the observation period that spanned three decades. The main cause of death was cardiovascular disease and this finding was consistent over time.

Variations in the epidemiology of systemic lupus erythematosus in southern Sweden.

OBJECTIVE: The epidemiology of systemic lupus erythematosus (SLE) within a defined region in southern Sweden was studied during the time period 1981-2006. Furthermore, whether the phenotypic expression of SLE changed during the study period was investigated. METHODS: Patients with suspected SLE were retrieved from diagnosis registries, hospital records and central laboratory databases. All new cases of SLE in this region were identified using validated retrieval methods and observed prospectively in a structured follow-up program. SLE disease manifestations, including classification criteria, were followed over time. RESULTS: A total of 174 cases were diagnosed with SLE during 1981-2006. In the first period of the study, from 1981 to 1993, the incidence of SLE was 5.0/100,000 inhabitants and in the second period of the study, 1994-2006, the annual incidence decreased to 2.8/100,000. During the first period the highest incidence was among females between the ages of 45 and 54 years; 15.1/100,000 inhabitants, which was reduced in the second period to 3.8/100,000. During the second period the highest age and sex specific incidence was among women between 25 and 34 years (6.6/100,000 inhabitants). The point prevalence of SLE on 31 December 1993 was 55/100,000 inhabitants compared with 31 December 2006, when it was 65/100,000 inhabitants. The phenotype of the disease did not vary significantly during the study period. CONCLUSION: The incidence rate of SLE in younger females remained stable from 1981 to 2006. However, in middle-aged women the incidence was substantially reduced in the latter half of the study period.