Inter-observer agreement of the physician’s global assessment of disease activity in children with juvenile idiopathic arthritis

A. Falcone, R. Cassone, F. Rossi, A. Pistorio1, A. Martini, A. Ravelli

Dipartimento di Pediatria, Università di Genova, Pediatria II, Istituto di Ricovero e Cura a Carattere Scientifico G. Gaslini, Genova, Italy; and 1Servizio di Epidemiologia Clinica e Biostatistica, Direzione Scientifica, Istituto di Ricovero e Cura a Carattere Scientifico G. Gaslini, Genova, Italy.

ABSTRACT
Objective
To assess the inter-observer agreement in the physician's global assessment of overall disease activity (MD global) in a cohort of patients with juvenile idiopathic arthritis (JIA).

Methods
Forty consecutive patients with JIA, who were representative of a wide spectrum of disease activity and severity, were examined simultaneously by 4 observers. Observer 1 (who was the most experienced rheumatologist) carried out a routine rheumatologic examination of each patient including a complete articular assessment, and subsequently calculated in secrecy the MD global score on an anchored horizontal 10-cm VAS. Observers 2, 3 and 4 were present during the examination; afterwards they also scored in secrecy the MD global score for the patient. Agreement was measured by the intra-class correlation coefficient (ICC), using the score of Observer 1 as the gold standard. An ICC below 0.75 was considered unsatisfactory.

Results
The mean (SD) MD global scores for Observers 1, 2, 3, and 4 were 5.2 (3.4), 6.7 (3.9), 5.9 (3.5), and 5.6 (3.7), respectively. The level of agreement with Observer 1 in scoring was 0.83 for Observer 2, 0.88 for Observer 3, and 0.90 for Observer 4, indicating good agreement for all observers.

Conclusions
Our study shows a good inter-observer agreement in the physician’s global assessment of overall disease activity in patients with JIA. Analyses involving investigators from different countries are needed to determine whether these results can be generalized.

Key words
Juvenile idiopathic arthritis, physician’s global assessment, visual analogue scale, disease activity.

Alessandra Falcone, MD; Raffaella Cassone, MD; Federica Rossi, MD; Angela Pistorio, MD, PhD; Alberto Martini, MD; Angelo Ravelli, MD.

Please address correspondence to: Angelo Ravelli, MD, Pediatria II, Istituto G. Gaslini, Largo G. Gaslini no. 5, 16147 Genova, Italy.
E-mail: angeloravelli@ospedale-gaslini.ge.it

Clin Exp Rheumatol 2005; 23: 113-116.
© CLINICAL AND EXPERIMENTAL RHEUMATOLOGY 2005.