A multinational study of adults with Still’s disease  found that calculating their systemic score at baseline significantly predicted the patients risk for life-threatening outcomes (MAS or death).

Two cohorts of adult-onset Still’s disease (AOSD) included the GIRRCS (Gruppo Italiano Di Ricerca in Reumatologia Clinica e Sperimentale) AOSD-study group and AIDA (AutoInflammatory Disease Alliance) Network Still’s Disease Registry patients. The life-threatening outcomes were defined as mortality, and/or macrophage activation syndrome (MAS), a secondary hemophagocytic lymphohistiocytosis.

There were a total of 597 Still’s disease patients , with a mean age of 36.6±17.3 years (male 44%).  The Systemic Score (of Pouchot et al) was defined based on the presence of 12 manifestations (one point each): fever,  typical rash, pleuritis, pneumonia, pericarditis,  hepatomegaly or abnormal liver function tests,  splenomegaly, lymphadenopathy, leukocytosis > 15000/mm3, sore throat, myalgia, and abdominal pain (maximum score: 12 points).

The systemic score significantly predicted:

• life-threatening outcomes (OR: 1.24, 95%CI:1.07–1.42; p=0.004). 
• systemic score ≥7 was more predictive of life-threatening evolution (OR: 3.36, 95%CI:1.81–6.25; p<0.001). 

Use of this tool demonstrated the importance of liver involvement (OR: 1.68, 95%CI:1.48–2.67; p=0.031) and lung disease (OR: 2.12, 95%CI:1.14–4.49; p=0.042) on serious outcomes.

The clinical utility of the systemic score was demonstrated in evaluating of Still’s disease patients are at higher risk of life-threatening evolution.