The Revised Five Factor Score (rFFS) is a clinical calculator used for prognosis in patients with systemic necrotizing vasculitis. This scoring system is specifically designed for patients diagnosed with this rare autoimmune disease, which causes inflammation and damage to blood vessels throughout the body.

The rFFS is used to predict the likelihood of patient survival at five years following diagnosis. It takes into account five key factors: age over 65 years, cardiac symptoms, gastrointestinal involvement, renal insufficiency, and the absence of ear, nose, and throat symptoms. Each factor is assigned a score, and the total score is used to estimate prognosis.

The rFFS is not applicable to patients without a confirmed diagnosis of systemic necrotizing vasculitis. It also may not be as accurate in patients with other significant comorbidities or in those who have had the disease for a long time before diagnosis, as these factors can influence the course of the disease and the patient's overall prognosis.

Revised Five Factor Score for prognosis of systemic necrotizing vasculitis (rFFS)

# Criteria
 A. Age > 65 years (+1)
B. Renal insufficiency (stabilized peak creatinine >= 150 mcmol/L) (+1)
C. Cardiac insufficiency (+1)
D. GI involvement (+1)
E. Absence of ENT manifestations (+1)

# Conditions
- score == 0
- score == 1
- score >= 2

The Five-Factor Score revisited: assessment of prognoses of systemic necrotizing vasculitides based on the French Vasculitis Study Group (FVSG) cohort.