All-cause, cause-specific and age-specific standardised mortality ratios of patients with systemic lupus erythematosus in Ontario, Canada over 43 years (1971–2013)

Abstract

BackgroundSurvival in systemic lupus erythematosus (SLE) has improved substantially in the last 50 years. The aim of the present study was to assess the evolution of the all-cause, cause-specific and age-specific standardised mortality ratios (SMRs) of patients with lupus in Ontario, Canada.Patients and methodsBetween 1971 and 2013, 1732 patients were followed in the Toronto Lupus Clinic. Causes of death were retrieved from death certificates, autopsy reports, hospital records or the records of the family physicians. They were categorised as atherosclerotic, infectious, malignancy, active lupus and others. For the calculation of the SMR (indirect standardisation method), data from the general population of Ontario, Canada were used (Statistics Canada).ResultsTwo hundred and forty-nine patients (205 women) died (infections 24.5%, atherosclerosis 15.7%, active lupus 13.3%, malignancy 9.6%); mean age was 53.2±16.6 years and mean disease duration 15.2±11.7 years. The all-cause SMR was substantially decreased from the 1970s (13.5, 95% CI 8.6 to 18.5) to recent years (2.2, 95% CI 1.4 to 3.1). Similar trends were observed for atherosclerosis, infections and malignancies over time. The all-cause age-specific SMR was particularly high in younger (19–39 years old) patients (SMR=12.4, 95% CI 9.7 to 15.1) as compared with individuals older than 40 years (SMR=3.1, 95% CI 2.6 to 3.6). The cause-specific SMR was also higher in younger patients, particularly for infections and malignancies.ConclusionsThe all-cause and cause-specific SMR significantly decreased over time, likely reflecting the advances in the management of SLE and certain comorbidities. The all-cause and cause-specific SMR was particularly high for younger patients (<40 years old).

Outcomes of membranous and proliferative lupus nephritis – analysis of a single-centre cohort with more than 30 years of follow-up

“…Renal survival and mortality rates in our patients are similar to most other cohorts [ 22 ], as are the main causes of death [ 23–26 ]. In contrast, a Japanese study with 186 LN patients showed lower ESRD and mortality rates; however, more than one-third of the patients included had mesangial LN (class I and II), which is associated with a significantly better prognosis and does not require the same treatment as class III, IV or V [ 27 ].…”

Large-scale mortality gap between SLE and control population is associated with increased infection-related mortality in lupus

“…In line with other observations, the overall SMR was found to be 1.63 (‘All incident SLE patients’) and 2.09 (‘Treated SLE patients’) in our study. While a recent study investigating a longer time period demonstrated a significant reduction of all-cause and cause-specific SMR compared with the general population from 13.5 to 2.2 [ 24 ] and early survival among SLE patients has improved substantially, epidemiological studies still show an increased mortality rate in SLE compared with the general population [ 25–27 ]. A wide range of recent studies report values of SMR for the adult SLE population between 2.4 and 3.5 in Europe and North America [ 18 , 20 ], and up to 2.58–5.25 in Asian countries [ 18 , 19 , 28 ].…”

“…Björnådal et al found that cardiovascular mortality remained high, especially in younger population between 1964 and 1995 [ 32 ]. Tselios et al [ 24 ] used ICD-10 codes that cover the atherosclerotic diseases (both cardiac or cerebrovascular) and found that the cause-specific SMR decreased from 8.3 in the 1980s to 3.2 in the most recent years (2010–13), with an average of 4.7. An SMR of 2.97 for coronary heart disease and stroke was reported in Sweden for the period of 1964–95 [ 32 ].…”

“…Regarding the infection-related mortality, our results show a significant positive interaction for infection-related mortality in SLE. Tselios et al reported an SMR of 4.4 [ 24 ], likewise, two meta-analyses reported an SMR of 4.98 [ 18 , 19 ]. Bernatsky et al reported an infection-related SMR of 5.0 [ 20 ].…”

“…Importantly, we observed an increased risk of death due haematological malignancies when studying all patients in the 6-month period prior to death. Previously presented studies and meta-analyses reported a not significantly increased risk of malignancy-related death (SMRs of 1.19, 1.16, 0.8 and 1.4) [ 18–20 , 24 ].…”