Objective The Systemic Lupus Collaborating Clinics (SLICC) revised and validated the American College of Rheumatology (ACR) SLE classification criteria in order to improve clinical relevance, meet stringent methodology requirements and incorporate new knowledge in SLE immunology. Methods The classification criteria were derived from a set of 702 expert-rated patient scenarios. Recursive partitioning was used to derive an initial rule that was simplified and refined based on SLICC physician consensus. SLICC validated the classification criteria in a new validation sample of 690 SLE patients and controls. Results Seventeen criteria were identified. The SLICC criteria for SLE classification requires: 1) Fulfillment of at least four criteria, with at least one clinical criterion AND one immunologic criterion OR 2) Lupus nephritis as the sole clinical criterion in the presence of ANA or anti-dsDNA antibodies. In the derivation set, the SLICC classification criteria resulted in fewer misclassifications than the current ACR classification criteria (49 versus 70, p=0.0082), had greater sensitivity (94% versus 86%, p<0.0001) and equal specificity (92% versus 93%, p=0.39). In the validation set, the SLICC Classification criteria resulted in fewer misclassifications (62 versus 74, p=0.24), had greater sensitivity (97% versus 83%, p<0.0001) but less specificity (84% versus 96%, p<0.0001). Conclusions The new SLICC classification criteria performed well on a large set of patient scenarios rated by experts. They require that at least one clinical criterion and one immunologic criterion be present for a classification of SLE. Biopsy confirmed nephritis compatible with lupus (in the presence of SLE autoantibodies) is sufficient for classification.

Objective. To develop and perform an initial validation of a damage index for systemic lupus erythematosus (SLE). Methods.A list of items considered to reflect damage in SLE was generated through a nominal group

Objective. To test the reliability of the Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) Damage Index and the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) in the assessment of patients with SLE. Methods. Ten patients with SLE, representing a spectrum of damage and activity, were included. Each patient was examined by 6 of 10 physicians from 5 countries, representing 10 lupus clinics. The SLICC/ACR Damage Index was used to assess accumulated damage, and the SLEDAI was used to assess disease activity. The order of the patients and physicians was randomized according to a Youden square design. Results. The SLICC/ACR Damage Index detected differences among patients (P < 0.001). There was no detectable observer difference (P = 0.933), and there was no order effect (P = 0.261). Similar results were obtained with the SLEDAI. There was concordance in the SLICC/ACR Damage Index among observers, despite a wide spectrum of disease activity detected by the SLEDAI. Conclusion. Physicians from different centers are able to assess patients with SLE in a reproducible way, using the SLEDAI to assess disease activity and the SLICC/ACR Damage Index to assess accumulated damage.

Objective. To examine mortality rates in the largest systemic lupus erythematosus (SLE) cohort ever assembled.Methods. Our sample was a multisite international SLE cohort (23 centers, 9,547 patients). Deaths were ascertained by vital statistics registry linkage. Standardized mortality ratio (SMR; ratio of deaths observed to deaths expected) estimates were calculated for all deaths and by cause. The effects of sex, age, SLE duration, race, and calendar-year periods were determined.Results. The overall SMR was 2.4 (95% confidence interval 2.3-2.5). Particularly high mortality was seen for circulatory disease, infections, renal disease, non-Hodgkin's lymphoma, and lung cancer. The highest SMR estimates were seen in patient groups character-

Background and aimsWe studied damage accrual and factors determining development and progression of damage in an international cohort of systemic lupus erythematosus (SLE) patients.MethodsThe Systemic Lupus International Collaborating Clinics (SLICC) Inception Cohort recruited patients within 15 months of developing four or more 1997 American College of Rheumatology (ACR) criteria for SLE; the SLICC/ACR damage index (SDI) was measured annually. We assessed relative rates of transition using maximum likelihood estimation in a multistate model. The Kaplan–Meier method estimated the probabilities for time to first increase in SDI score and Cox regression analysis was used to assess mortality.ResultsWe recruited 1722 patients; mean (SD) age 35.0 (13.4) years at cohort entry. Patients with damage at enrolment were more likely to have further worsening of SDI (SDI 0 vs ≥1; p<0.001). Age, USA African race/ethnicity, SLEDAI-2K score, steroid use and hypertension were associated with transition from no damage to damage, and increase(s) in pre-existing damage. Male gender (relative transition rates (95% CI) 1.48 (1.06 to 2.08)) and USA Caucasian race/ethnicity (1.63 (1.08 to 2.47)) were associated with SDI 0 to ≥1 transitions; Asian race/ethnicity patients had lower rates of new damage (0.60 (0.39 to 0.93)). Antimalarial use was associated with lower rates of increases in pre-existing damage (0.63 (0.44 to 0.89)). Damage was associated with future mortality (HR (95% CI) 1.46 (1.18 to 1.81) per SDI point).ConclusionsDamage in SLE predicts future damage accrual and mortality. We identified several potentially modifiable risk factors for damage accrual; an integrated strategy to address these may improve long-term outcomes.