Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.

Juvenile Idiopathic Arthritis (JIA) Classification: An Audit of a Tertiary Paediatric Rheumatology Service's Adherence to ILAR (Edmonton 2001) Classification Criteria.

J. Cox2,  Angela, Chin Lim1,  Sern, C. Allen3,  Roger, D. Akikusa1,  Jonathan, Munro1,  Jane

Royal Children's Hospital, Melbourne, Victoria, Australia
Royal Children's Hospital, Melbourne, Australia
Royal Childrens Hospital, Melbourne, Australia


The International League of Associations for Rheumatology (ILAR) classification criteria for Juvenile Idiopathic Arthritis are widely used in prospective and retrospective studies of chronic arthritis in childhood. They define seven subtypes of chronic arthritis based on strict inclusion and exclusion criteria involving both clinical and laboratory parameters, some of which may not appear relevant in certain clinical situations and therefore may not be tested for in daily practice. The inaccuracy in patient classification that this may produce could have a significant impact on the results of research conducted using such cohorts.


To determine whether patients newly diagnosed with JIA within a year at the Royal Children's Hospital (RCH), Melbourne met strictly applied ILAR classification criteria for their assigned JIA subtype.


All newly diagnosed JIA patients seen in the Rheumatology Department at the RCH in 2009 were identified using the RCH rheumatology database. A retrospective review of the clinical and laboratory data collected for these patients was performed. The JIA subtype entered into the database for each patient was checked against ILAR classification inclusion and exclusion criteria. If they did not meet the designated subtype criteria or could not be classified because of incomplete data, the reason was recorded.


56 patients were included (35F, 21M). The diagnoses recorded in the database were Oligoarthritis 32(57%), Polyarthritis Rheumatoid Factor negative (RF-ve) 10(17.9%), Systemic arthritis 3(5.4%), Extended Oligoarthritis 2(3.6%), Polyarthritis Rheumatoid Factor positive (RF +ve), 2(3.6%), Psoriatic arthritis 2(3.6%), Enthesitis-related Arthritis (ERA) 1(1.8%) and Undifferentiated arthritis 4(7%). Only 13(23%) had complete clinical and laboratory information allowing classification by ILAR criteria. In 11 patients this matched the diagnosis assigned in the database. Two patients were reassigned to another subtype; one from Oligoarthritis to Undifferentiated arthritis due to the presence of psoriasis in a first degree relative, the other from Polyarthritis RF +ve to Polyarthritis RF-ve due to a negative follow-up RF. 43 patients had insufficient information to allow classification using ILAR criteria. The commonest reason was failure to test for RF, in 34(60%) patients. The majority of these patients, 20(58%), were Oligoarthritis. The second most common reason was an incompletely documented family history in 17(30%) patients, followed by 7(14%) patients who had not had a HLAB27 performed or documented.


The strict application of the ILAR classification criteria for JIA requires information that may not be routinely collected in daily clinical practice. At our centre collection of all data required to classify children with chronic arthritis according to strictly applied ILAR criteria was uncommon, seen in less than 25% of patients. We suggest that for centres wishing to participate in research involving patients with JIA that a minimum dataset be devised and applied to all newly diagnosed JIA patients to enable accurate ILAR classification.

To cite this abstract, please use the following information:
J. Cox, Angela, Chin Lim, Sern, C. Allen, Roger, D. Akikusa, Jonathan, Munro, Jane; Juvenile Idiopathic Arthritis (JIA) Classification: An Audit of a Tertiary Paediatric Rheumatology Service's Adherence to ILAR (Edmonton 2001) Classification Criteria. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :226
DOI: 10.1002/art.27995

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