The European Scleroderma Trials and Research group (EUSTAR) task force for the development of revised activity criteria for systemic sclerosis: derivation and validation of a preliminarily revised EUSTAR activity index.
BACKGROUND
Validity of European Scleroderma Study Group (EScSG) activity indexes currently used to assess disease activity in systemic sclerosis (SSc) has been criticised.


METHODS
Three investigators assigned an activity score on a 0-10 scale for 97 clinical charts. The median score served as gold standard. Two other investigators labelled the disease as inactive/moderately active or active/very active. Univariate-multivariate linear regression analyses were used to define variables predicting the 'gold standard', their weight and derive an activity index. The cut-off point of the index best separating active/very active from inactive/moderately active disease was identified by a receiver-operating curve analysis. The index was validated on a second set of 60 charts assessed by three different investigators on a 0-10 scale and defined as inactive/moderately active or active/very active by other two investigators. One hundred and twenty-three were investigated for changes over time in the index and their relationships with those in the summed Medsger severity score (MSS).


RESULTS
A weighted 10-point activity index was identified and validated: Δ-skin=1.5 (Δ=patient assessed worsening during the previous month), modified Rodnan skin score (mRss) >18=1.5, digital ulcers=1.5, tendon friction rubs=2.25, C-reactive protein >1 mg/dL=2.25 and diffusing capacity of the lung for CO (DLCO) % predicted <70%=1.0. A cut-off ≥2.5 was found to identify patients with active disease. Changes in the index paralleled those of MSS (p=0.0001).


CONCLUSIONS
A preliminarily revised SSc activity index has been developed and validated, providing a valuable tool for clinical practice and observational studies.
Rheumatology Section, Department of Clinical and Experimental Medicine, Second University of Naples, Naples, Italy.
Gabriele
G
Valentini
Rheumatology Section, Department of Clinical and Experimental Medicine, Second University of Naples, Naples, Italy.
Michele
M
Iudici
Department of Rheumatology, Basel University, Basel, Switzerland.
Ulrich A
UA
Walker
Department of Rheumatology, Basel University, Basel, Switzerland.
Veronika K
VK
Jaeger
Division of Rheumatology, Jewish General Hospital, McGill University, Montreal, Quebec, Canada.
Murray
M
Baron
Department of Rheumatology, 12 de Octubre University Hospital, Madrid, Spain.
Patricia
P
Carreira
Department of Rheumatology and Immunology, University of Pécs, Medical Centre, Pécs, Hungary.
László
L
Czirják
Division of Medicine, Centre for Rheumatology and Connective Tissue Disease, Royal Free Campus, University College London, London, UK.
Christopher P
CP
Denton
Department of Rheumatology, University Hospital Zurich, Zurich, Switzerland.
Oliver
O
Distler
Internal Medicine Department, Claude Huriez Hospital, Lille University, Lille, France.
Eric
E
Hachulla
NIHR Manchester Musculoskeletal Biomedical Research Unit, Centre for Musculoskeletal Research, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK.
Ariane L
AL
Herrick
Department of Rheumatology and Internal Medicine, Medical University of Bialystok, Bialystok, Poland.
Otylia
O
Kowal-Bielecka
Department of Medicine, St. Joseph's Health Care, University of Western Ontario, London, Ontario, Canada.
Janet
J
Pope
Department of Rheumatology and Clinical Immunology, Justus-Liebig University Giessen, Bad Neuheim, Germany.
Ulf
U
Müller-Ladner
Clinic for Rheumatology, University of Lübeck, Lübeck, Germany.
Gabriela
G
Riemekasten
Department of Rheumatology and Clinical Immunology, University Hospital Charité, Berlin, Germany.
Jerome
J
Avouac
Department of Rheumatology and Clinical Immunology, Justus-Liebig University Giessen, Bad Neuheim, Germany.
Marc
M
Frerix
Department of Rheumatology, University Hospital Zurich, Zurich, Switzerland.
Suzana
S
Jordan
Department of Rheumatology and Immunology, University of Pécs, Medical Centre, Pécs, Hungary.
Tünde
T
Minier
Department of Rheumatology and Clinical Immunology, University Hospital Charité, Berlin, Germany.
Elise
E
Siegert
Division of Medicine, Centre for Rheumatology and Connective Tissue Disease, Royal Free Campus, University College London, London, UK.
Voon H
VH
Ong
Rheumatology Section, Department of Clinical and Experimental Medicine, Second University of Naples, Naples, Italy.
Serena
S
Vettori
Rheumatology A Department, INSERM U1016 UMR8104, Cochin Hospital, Paris Descartes University, Paris, France.
Yannick
Y
Allanore
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005060:Europe / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D015203:Reproducibility of Results; D012595:Scleroderma, Systemic / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D055815:Young Adult
Autoimmune Diseases; Disease Activity; Systemic Sclerosis