Describing & Predicting Physical Functional Disability in Juvenile Idiopathic Arthritis

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Presentation Number:913

Poster Board Number:145

Presentation Time:11/9/2007 8:00:00 AM

Title:Describing and Predicting Physical Functional Disability in Juvenile

Idiopathic Arthritis: A Longitudinal Study

Category:11. Pediatric rheumatology clinical and therapeutic disease

Author(s):Silvia Magni-Manzoni1, Pistorio2, Elena Labò1, Serena

Panigada2, Pablo -Munitis2, Giovanni Filocamo2, Chiara Visconti1,

Stefania Viola2, Alberto i2, Angelo Ravelli2. 1IRCCS Policlinico San

Matteo, Pavia, Italy; 2IRCCS G Gaslini, Genova, Italy

Objective. To describe the longitudinal course of physical functioning in

children with juvenile idiopathic arthritis and identify predictors of

long-term functional impairment.

Methods. 227 patients had 2 or more Childhood Health Assessment

Questionnaires (CHAQ) completed by a parent. At each questionnaire

administration, patients were assigned to 1 of 3 functional disability

states, based on their functional ability score.

For purposes of the analysis, CHAQ scores were divided into 3 categories:

0-0.49; 0.5-1.5; and 1.51-3, representing physical functional disability

states 1, 2, and 3, respectively. State 1 represented the absence of

disability, while states 2 a and 3 represented " mild-to-moderate " and

" severe " disability, respectively.

To characterize the rates of transitions to and from these 3 disability

states, we used a reversible multistate Markov model as framework. Predictor

variables included sex, onset age, JIA category, age at visit, disease

duration, presence of antinuclear antibodies, joint counts, acute phase

reactants, and initial disability state.

Results. 227 patients had 1356 CHAQ completed. Mean number of CHAQ per

patient was 6 (2-19) and mean follow-up was 4.1 years.

Initial disability state was 1, 2 and 3 in 49.8%, 40.1% and 10.1% of

patients respectively. Despite patient variability in the course of physical

functioning, the following 3 longitudinal patterns were observed:

1) a stable state of disability throughout the entire study period, with

27.8% and 3.5% of patients experiencing continued absence of disability or

persistently moderate disability, respectively;

2) a steady improvement or deterioration in disability over time (22.9% and

13 5.7% of patients, respectively);

3) a fluctuating course of disability, with both deterioration and

improvement (40.1% of patients).

Disability state at last visit was 1, 2 and 3 in 74%, 22.9%, and 3.1% of

patients, respectively. The strongest predictor variables were an age < 4.8

years and a restricted joint count > 10.

Conclusion. We found a wide within-patient and between-patient variability

in the longitudinal course of functional disability. In spite of this

variability, at last follow-up 3/4 of patients had no disability and a small

proportion had severe disability.

Children with early disease onset and a greater number of restricted joints

had the highest risk of developing long-term physical disability.

Disclosures: S. Magni-Manzoni, None.