The study population consisted of 49 consecutive patients with ERA who attended the outpatient clinic at a tertiary care referral hospital. ERA was defined according to the ILAR criteria : onset of arthritis before the 16th birthday and persisting for at least 6 weeks; arthritis and enthesitis, or arthritis or enthesitis with at least 2 of (a) presence of or a history of sacroiliac joint tenderness and/or inflammatory lumbosacral pain, (b) presence of HLA-B27 antigen, (c) onset of arthritis in a male over 6 years of age, (d) acute (symptomatic) anterior uveitis (e) history of ankylosing spondylitis, enthesitis related arthritis, sacroiliitis with inflammatory bowel disease, Reiter's syndrome, or acute anterior uveitis in a first-degree relative . By definition, patients with psoriasis or a history of psoriasis in the patient or first-degree relative, presence of IgM rheumatoid factor and systemic JIA are not included in ERA subtype . Other inclusion criteria were age more than 5 years and disease duration of greater than one year. Same Rheumatologist (PKS) examined all patients. Onset of symptoms was taken as the date of onset of disease.
JADI scores were calculated as described previously . The index is composed of articular (JADI-A) and extraarticular (JADI-E) damage. In the JADI-A, 36 joints or joint groups are assessed for the presence of damage: cervical spine, shoulders, elbows, wrists, individual metcarpophalangeal and proximal interphalangeal joints, hips, and knees; right and left temporomandibular joints, ankle and subtalar joints and metatarsophalangeal joint of each foot are considered as a single unit. The damage observed in each joint is scored as 1 in case of partial damage, or 2 in case of severe damage, ankylosis, or prosthesis. Contractures and other joint deformities are scored when they are completely explained by prior damage and are not due to active arthritis and are present for at least 6 months. For each joint, only the most severe lesions are scored. The maximum possible JADI-A score is 72.
For JADI-E, muscle atrophy, osteoporosis with fractures or vertebral collapse, avascular necrosis of bone, significant abnormality of the vertebral curve due to leg length discrepancy or hip contracture, significant leg length discrepancy or growth abnormality of a bone segment, striae rubrae, subcutaneous atrophy resulting from intraarticular corticosteroid injection, growth failure, pubertal delay, diabetes mellitus and amyloidosis are scored as 1 if present; ocular complications like cataract or other complications of uveitis were scored as 1 if present, 2 if surgery was required and 3 in case of legal blindness.
Abdominal fat pad analysis for amyloidosis was done if there was edema, anasraca, proteinuria or disproportionately increased ESR. Growth was assessed by plotting height and weight on standardized Indian pediatric growth charts. Growth failure was defined as the presence of two or more of the following: less then 3rd percentile height for age, growth velocity less than 3rd percentile for age or crossing at least 2 centile on growth chart . Delayed puberty was defined if no testicular enlargement occurred by 14 years of age.
Educational level achieved, loss of school years, functional status measured by HAQ-S  were also recorded. For the purposes of analysis, the HAQ-S score was divided into 4 categories: 0 = no disability, >0 and ≤ 0.5 = mild disability, >0.5 and ≤1.5 = moderate disability, and > 1.5 = severe disability . Hundred mm Visual Analogue Scale (VAS) was used for parent/patient's assessment of their disease.
Examination included physician's global assessment on 100 mm VAS, number of active joints as defined by presence of swelling (excluding bony swelling) or any two of limitation of motion (LOM), pain, heat, or tenderness and number of joints with limited range of motion (ROM); 67 joints were assessed .
Enthesitis was defined as discretely localized tenderness at the point of insertion of ligaments, tendons, joint capsules, or fascia to bone [12, 16]. Anterior lumbar flexion was assessed using the modified Schober's method [12, 17]. Reduced lumbar flexion was defined as values ≤ 6.5 cm in boys and ≤ 5.5 cm in girls [11, 18]. Inflammatory back pain was defined as lumbosacral spinal pain at rest, with morning stiffness that improved with movement [1, 12]. Erythrocyte Sedimentation rate (ESR) was measured by Westergren method. Remission was defined as described previously .
We used SPSS (version 13) software for statistical analysis. Spearman's rank correlation coefficient (rS) was used to assess correlations among different parameters. Correlations > 0.7 were considered high, 0.4 to 0.7 moderate and <0.4 low [13, 20]. P values less than 0.05 were considered significant and less than 0.01 as highly significant.