Mortality in systemic sclerosis-a single centre study from the UK

This study aims to determine the cause and predictors of mortality in a cohort of patients with systemic sclerosis (SSc) and assess whether the mortality rate differs significantly from the general population. Patients enrolled onto the Royal National Hospital for Rheumatic Diseases Connective Tissue Disease database between 1999 and 2010 were included in this study. The NHS Strategic Tracing Service and UK Registry of Births, Marriages and Deaths were used to establish date and cause of deaths. A retrospective case note review collected information on clinical phenotype and serology. A standardised mortality ratio (SMR) was calculated and survival was determined using Kaplan-Meier estimates. Univariate and multivariate predictors of survival were assessed using proportional hazards regression modelling. Amongst this cohort of 204 patients (25 males, 40 diffuse SSc), the mean age at diagnosis was 51.6 years (SD13.7) and the mean duration of follow-up was 12.5 years (SD 8.8 years). In the deceased group (53 patients), the mean age of death was 72.0 years (SD 12.3 years). The mean disease duration at death was 14.2 years (SD 8.5 years). The overall SMR was 1.34 (95 % confidence interval (CI) 1.00-1.75). The SMR was higher in males (1.54 [95 % CI 0.67-3.04] vs. 1.30 [95 % CI 0.95-1.74]). The leading causes of death in this cohort were infection, respiratory disease and malignancy. The most common cause of SSc-related mortality was pulmonary complications. Factors adversely affecting survival were older age at diagnosis, male gender, interstitial lung disease (ILD) and anti-RNA polymerase III antibody. The mortality rate of our cohort, who had predominantly limited disease, was higher than that of the general population; although not as high as reported in previous retrospective studies.