Disease activity score for still's disease.

OBJECTIVE

To develop the Still's Disease Activity Score (SDAS).

METHODS

We used data from the prospective adult-onset Still's disease cohort study and evaluated the disease activity. An expert group selected the most frequent, reproducible, and objective variables significantly modified in statistical analysis when comparing patients in the active group and in the remission group. These criteria were weighted to design the Still's Disease Activity Score (SDAS). The Delphi method was used to appreciate the level of disease activity. Total SDAS was calculated for each patient and compared to final consensus experts.

RESULTS

At the diagnosis, all patients had an active disease (n = 80), while 48 patients were in remission at 6 months. The SDAS criteria were weighted as follows: fever ≥ 38.5 °C (1 point), rash (1 point), joint involvement (arthralgia: 1 point, swollen joints count "SJC": 1-3 SJC: 2 points, ≥ 4 SJC: 3 points), physician global assessment VAS ≥ 5/10 or a raise in physician VAS ≥ 2/10 (3 points), patient VAS ≥ 5 or a raise in patient VAS ≥ 2/10 (1 point), and CRP (> 10 mg/l: 1 point, ≥ 100 mg/l: 2 points). At 6 months, the consensus was achieved for 76 (95%) patients with 40 in remission (0-1 point), 8 in low disease activity (2-3 points), 16 in moderate disease activity (4-7 points), and 12 in severe disease activity (≥ 8 points).

CONCLUSION

The Still's Disease Activity Score is a valid and sensitive assessment of the disease activity and the therapeutic response in Still's disease, despite its heterogeneous manifestations and patterns with systemic and articular forms. Key Points • The Still's Disease Activity Score (SDAS) is a good simple tool to assess the activity of the disease in a stable state for a week. • The SDAS is developed specifically for Still's disease without the need for an application or a calculator to calculate SDAS in routine clinical practice. • SDAS is a composite score classifying the disease activity in remission, low disease activity, moderate disease activity, and severe disease activity despite its heterogeneous patterns (systemic and articular forms). • The SDAS is a valid, reliable, and sensitive score and can be useful to guide the therapeutic strategy in clinical practice and in research.