ARTHRITIS & RHEUMATISM Vol. 52, No. 7, July 2005, pp 2092–2102 DOI 10.1002/art.21119 © 2005, American College of Rheumatology Development and Validation of a Clinical Index for Assessment of Long-Term Damage in Juvenile Idiopathic Arthritis Stefania Viola, 1 Enrico Felici, 1 Silvia Magni-Manzoni, 2 Angela Pistorio, 3 Antonella Buoncompagni, 1 Nicolino Ruperto, 1 Federica Rossi, 1 Manuela Bartoli, 2 Alberto Martini, 1 and Angelo Ravelli 1 Objective. To develop and validate a clinical mea- sure of articular and extraarticular damage in patients with juvenile idiopathic arthritis (JIA). Methods. The Juvenile Arthritis Damage Index (JADI), which is derived from physical examination and a brief review of the patient’s clinical history, is com- posed of 2 parts: assessments of articular damage (JADI-A) and extraarticular damage (JADI-E). Instru- ment validation was accomplished by evaluating 158 JIA patients with disease duration of at least 5 years, seen consecutively over 21 months. The instrument’s feasibil- ity, face and content validity, construct and discrimina- tive ability, internal consistency, and interrater reliabil- ity were examined. Results. Among the 158 JIA patients, 47% and 37% had articular and extraarticular damage, respec- tively. The JADI was found to be feasible and to possess both face and content validity. The JADI-A score corre- lated highly with the number of joints with limited range of motion (Spearman’s r [r S ]  0.72) and correlated moderately with the Childhood Health Assessment Questionnaire score (r S  0.41), Steinbrocker func- tional classification (r S  0.50), and Poznanski’s score of radiographic damage (r S 0.54), thereby demon- strating good construct validity. Correlations with the JADI-E score were lower, owing to the heterogeneity of its items. The JADI-A discriminated well among differ- ent levels of disability. The internal consistency (Chron- bach’s alpha) of the JADI-A and JADI-E was 0.93 and 0.59, respectively. The intraclass correlation coefficients between pairs of independent observers ranged from 0.85 to 0.97. Conclusion. The JADI exhibited good reliability, construct validity, and discriminative ability and is therefore a valid instrument for the assessment of long-term damage in patients with JIA, in the context of both clinical management and research settings. Juvenile idiopathic arthritis (JIA) is a chronic and heterogeneous disease characterized by prolonged syno- vial inflammation that may lead to permanent alter- ations in joint structures. Permanent changes may also develop in extraarticular organs/systems, such as the eye (as a complication of chronic anterior uveitis) or the kidney (due to systemic amyloidosis), or may result from side effects of medications (1). This morbidity may have a relevant impact on the quality of life of patients and their families (2,3). In the outcome studies published so far (for review, see refs. 4 and 5), the long-term morbidity in JIA patients has been most frequently evaluated in terms of functional disability. Currently, the most widely used tool for assessment of functional status is the Childhood Health Assessment Questionnaire (C-HAQ) (6). How- ever, despite its advantages and widespread use, the C-HAQ has been shown to have specific limitations in research and clinical settings. First, it has been demon- strated to have a ceiling effect, with a tendency for scores to cluster at the normal end of the scale, particularly in patients with fewer joints involved (7,8). Second, its estimation of physical disability in patients with active disease can be inflated by symptoms of inflammation, particularly joint pain (9,10). Third, the parent’s obser- vation of the child’s physical function has been found to 1 Stefania Viola, MD, Enrico Felici, MD, Antonella Buoncom- pagni, MD, Nicolino Ruperto, MD, MPH, Federica Rossi, MD, Alberto Martini, MD, Angelo Ravelli, MD: Universita ` di Genova, IRCCS G. Gaslini, Genoa, Italy; 2 Silvia Magni-Manzoni, MD, Man- uela Bartoli, MD: Universita ` di Pavia, IRCCS Policlinico S. Matteo, Pavia, Italy; 3 Angela Pistorio, MD, PhD: Direzione Scientifica, IRCCS G. Gaslini, Genoa, Italy. Address correspondence and reprint requests to Angelo Ravelli, MD, Pediatria II, Istituto G. Gaslini, Largo G. Gaslini 5, 16147 Genoa, Italy. E-mail: angeloravelli@ospedale-gaslini.ge.it. Submitted for publication September 2, 2004; accepted in revised form March 23, 2005. 2092