Early damage as measured by the SLICC/ACR damage index is a predictor of mortality in systemic lupus erythematosus

Abstract

The aim of this study was to determine whether early damage accrued in SLE as measured by the SLICC/ACR Damage Index predicts mortality in an inception cohort of lupus patients that have been followed prospectively in a single centre. SLE patients from the University of Toronto Lupus Clinic presenting within 1 y of their diagnosis prior to 1988 were included. This enabled all patients to be potentially followed for at least 10 y. Yearly SLICC/ACR Damage Index scores were determined for each patient. Early damage was defined as a score 1 and no damage as a score of 0 at the initial assessment. Log rank test was used to compare the survival experience between those with and without damage, with all patients being censored at 10 y. Two-hundred and sixty-three patients were identified in this inception cohort who were followed for 10 y. One-hundred and ninety patients (72%) had a SLICC/ACR Damage Index score of 0 (no damage) while 73 patients (28%) had at least one SLICC/ACR Damage Index item scored (early damage). Twenty-five percent of lupus patients who exhibited damage at their first SLICC/ACR Damage Index assessment died within 10 y of their illness as compared to only 7.3% who had no early damage (log rank P-value = 0.0002). SLE patients who died within 10 y were more likely to have renal damage (P = 0.013), and a trend toward more cardiovascular disease (P = 0.056), compared to patients who were alive. Early damage as reflected by the initial SLICC/ACR Damage Index is associated with a higher rate of mortality.