Mortality and prognostic factors in Spanish patients with systemic sclerosis

Objective. To determine survival and mortality in a cohort of Spanish patients with scleroderma (systemic sclerosis, SSc) and to analyse whether survival is influenced by demographic, clinical or immunological variables or the extent of skin involvement. Methods. The study included 79 patients diagnosed with SSc and taking part in a study to determine the extent of sclerosis, visceral involvement and immunological alterations. We studied the number of observed and expected deaths (the expected number being based on age- and sex-specific rates in the background population) and derived standardized mortality ratios with their 95% confidence intervals (CI). Cumulative survival after onset of the first symptom was estimated according to the Kaplan-Meier method. The Cox method was used to identify the prognostic factors. Results. The mortality rate was 0.0249 deaths per person-year. Survival at 15 yr was 0.62 (95% CI 0.410-0.778). The standardized mortality ratio was 429.4% (95% CI 222-750). On crude analysis, lung involvement [forced vital capacity (FVC) <70%, pulmonary hypertension], SSc renal crisis, an active capillaroscopic pattern, pericardial effusion and age over 60 yr at diagnosis were associated with shorter survival. On multivariate analysis, only age at diagnosis over 60 yr, FVC <70% and SSc renal crisis were independent prognostic factors. Conclusions. The mortality rate associated with SSc showed a four-fold increase compared with the background population. Lung involvement and sclerodermal renal crisis were found to be independently associated with reduced survival.