Objective: To test the predictability of the adjusted mean Systemic Lupus Erythematosus Disease Activity Index-2K (AMS) for main outcomes in systemic lupus erythematosus (SLE), namely presence of damage, coronary artery disease (CAD), and avascular necrosis (AVN).
Methods: Included in this study are patients with regular followup from the University of Toronto Lupus Clinic. This was defined as a minimum of 3 visits and no absence exceeding 18 consecutive months. For each visit, AMS was evaluated. The ability of the AMS to predict each of the main outcomes was evaluated through time-dependent covariate survival analysis. Adjustments to the regression models were made to include other risk factors such as sex, age at diagnosis (AGE), SLEDAI-2K at presentation (SLEDAI), disease duration (DD), and use of corticosteroids, immunosuppressives (IM), or antimalarials (AM).
Results: Five hundred and seventy-five patients were included covering the period from 1970 to 2002. A total of 325 developed damage, 55 had CAD, and 68 had AVN. Presence of damage was not associated with sex, SLEDAI, or AM but was significantly associated with AMS, AGE, DD, and use of steroids or IM (all p < 0.001). CAD was not associated with SLEDAI or use of steroids or AM but with all other variables AMS (p = 0.046), sex (p = 0.009), AGE (p < 0.0001), DD (p < 0.0001), and IM (p = 0.035). Predictors of AVN were DD (p = 0.032) and IM (p < 0.0001) but not sex, AGE, use of steroids, AM, SLEDAI, or AMS.
Conclusion: AMS is associated with the presence of damage and CAD. It is not associated with AVN.