High predictive value of the Systemic Lupus International Collaborating Clinics/American College of Rheumatology damage index for survival in systemic lupus erythematosus.

OBJECTIVE

We previously reported high Systemic Lupus International Collaborating Clinics (SLICC) scores in fatal cases of systemic lupus erythematosus (SLE) from our inception cohort. This study was done to clarify if the SLICC damage scores 5 years after diagnosis predicted the outcome.

METHODS

We studied 80 patients with SLE (70 women, 10 men), all enrolled and diagnosed during the years 1981 through 1991 in our inception cohort, and all alive 5 years after inclusion into the cohort. In all patients the SLICC/American College of Rheumatology (ACR) damage index (DI) was scored at 5 years after SLE diagnosis, and these scores were tested for predictive value. The outcomes were survival or late mortality within the following median observation period of 7 years. All surviving patients were followed through 1999, and no patient was lost to followup.

RESULTS

At study entry, 5 years after the diagnosis of SLE, 37 patients had no damage to score with SLICC. Of the remaining 43 patients, 25 had a score of 1 and 18 had a score of 2 or more. In total, 14 fatalities occurred within 7 years after study entry, 7 among the 18 with initial SLICC/ACR DI of 2 or more compared with 7 fatalities among the 62 with less or no damage (p < 0.01). Cardiovascular or cerebrovascular SLICC/ACR DI items were more common in fatal cases than in survivors (p < 0.001). A SLICC score at 5 years of 2 or more increased the relative risk for fatality by 3.4 (95% CI 1.5-14.4), and had a predictive value of 38%. A SLICC score of 0 at 5 years gave an odds ratio in favor of survival of 0.06 (95% CI 0.0-0.5) and had a predictive value for survival of 97%. During an extended followup for one more year the predictive value of damage for fatalities was even more pronounced (p = 0.003, log-rank).

CONCLUSION

SLICC damage scores registered 5 years after SLE diagnosis have a high predictive value for survival during the following median observation time of 7 years. These data provide strong evidence that the items included in the SLICC score are clinically relevant.