Background and aims To identify whether a SLEDAI-2K score ≥10, herein termed the High Disease Activity State (HDAS), might have utility as a prognostic factor amongst patients with Systemic Lupus Erythematosus (SLE).

Methods Using clinical data collected via the Monash Lupus Clinic we assessed the association of ever experiencing HDAS with adverse clinical outcomes and the association of sociodemographic and disease characteristics with the odds of ever experiencing HDAS. Logistic regression or generalised estimating equations were used for the analyses. For analyses of longitudinal outcomes, associations were adjusted for observation time.

Results Overall, 211 patients meeting SLE classification criteria were observed for a median of 4.5 years (range: 1–7.9 years); 42.7% experienced HDAS at least once during this time. The median time to first HDAS was 9 months after enrolment (range 0–6.7 years). Being diagnosed with SLE at ≥45 years of age was associated with reduced odds of experiencing HDAS amongst female patients (p=0.004). Autoantibody-positivity for anti-dsDNA was strongly associated with increased odds of ever experiencing HDAS (p<0.001). Ever experiencing HDAS was associated with increased odds of having an Adjusted Mean SLEDAI score in the highest quartile, experiencing a greater number of flares and of accruing damage (overall and particularly renal damage) over the observation period (p≤0.003 for all). Patients ever experiencing HDAS were also more likely to experience neuropsychiatric, renal and vasculitis disease activity over the observation period (p≤0.001 for all).

Conclusions Patients who ever experience HDAS represent a distinct clinical cohort with worse longitudinal disease outcomes.