Arthritis & Rheumatism, Volume 63,
November 2011 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Chicago, Illinois November 4-9, 2011.


Evaluation of the Association Between Ethnicity and Disease Activity and Severity in a Large Cohort of Patients with Juvenile Idiopathic Arthritis.

Pelajo1,  Christina F., Angeles-Han2,  Sheila, Prahalad3,  Sampath, Sgarlat1,  Caitlin M., Davis1,  Trevor, Miller1,  Laurie C., Lopez-Benitez1,  Jorge M.

Floating Hospital for Children at Tufts Medical Center, Boston, MA
Emory University, Atlanta, GA
Emory Children's Center, Atlanta, GA

Background/Purpose:

The impact of ethnicity on disease activity and severity in patients with juvenile idiopathic arthritis (JIA) is not well understood. Studies in large samples are needed to explore this association, since this could affect the future care of minorities with JIA. The aims of this study were to examine the association between ethnicity and disease activity in patients with JIA, and to determine the association of ethnicity with disease severity and disability in this population.

Methods:

CARRAnet, a US database containing information (collected between May 10 and Jun 11) on almost 3,000 subjects with JIA, was used. Demographic variables were compared between Hispanic (or Latino) patients and non-Hispanic patients. Mann-Whitney and Chi-square tests were used to compare indicators of disease activity (number of active joints, physician assessment of disease activity, parent/subject assessment of disease activity, and parent/subject pain score), as well as imaging evidence of joint damage, and Childhood Health Assessment Questionnaire (CHAQ) scores between ethnicities. A linear regression model was used to determine the association of ethnicity with number of active joints in JIA.

Results:

The sample analyzed included 2,704 patients with JIA (277 Hispanic and 2,427 non-Hispanic). Table 1 shows the demographic variables by ethnicity. Income and health insurance status were higher in non-Hispanics. RF-positive polyarticular JIA, positive RF and anti-CCP, as well as use of systemic steroids were more frequent in Hispanics.

Table 1. Demographic variables

VariableHispanicNon-Hispanicp-value
Age at baseline visit (mean ± SD)11.3 ± 5.211.5 ± 4.70.59
Age at onset of symptoms (mean ± SD)6.7 ± 4.56.4 ± 4.40.28
Age first seen by pediatric rheumatologist (mean ± SD)7.7 ± 4.87.3 ± 4.60.23
Gender (females) % (N)74 (206)73 (1765)0.56
Income (US$) % (N)  <0.0001
<25,00020 (56)10 (234) 
25,000–49,99923 (64)14 (348) 
50,000–74,99913 (36)16 (386) 
75,000–99,99911 (31)14 (343) 
100,000–150,00011 (30)19 (468) 
Above 150,0005 (13)12 (286) 
Unknown17 (46)15 (361) 
Health insurance % (N)95 (264)98 (2364)0.01
JIA subtype % (N)  <0.0001
Enthesitis-related arthritis8 (21)11 (255) 
Oligoarticular extended6 (17)9 (206) 
Oligoarticular persistent26 (73)27 (647) 
Polyarticular RF-23 (63)30 (728) 
Polyarticular RF+18 (50)6 (144) 
Psoriatic arthritis4 (10)6 (157) 
Systemic-onset11 (31)9 (208) 
Undifferentiated3 (8)2 (53) 
Laboratory tests % (N)
Positive ANA44 (120)44 (1052)0.06
Positive HLA-B276 (16)8 (185)0.48
Confirmed RF positive13 (32)4 (92)<0.0001
Anti-CCP positive11 (28)4 (83)<0.0001
Treatment % (N)44 (80)43 (706)0.02
Use of systemic steroids18 (32)12 (195) 
-Prior76 (210)77 (1859) 
-Current48 (132)46 (1100)0.59
Use of DMARD ever  0.75
Use of biologic ever

In the univariate analysis the number of active joints, the physician assessment of disease activity, and the parent subject/assessment of disease activity did not differ between ethnicities. However, the parent/subject pain score was significantly higher (worse) in Hispanics (3.0±2.9) than in non-Hispanics (2.5±2.6) (p=0.02). In the analysis of disability and disease severity, CHAQ was significantly higher (worse) in Hispanic patients (0.5±0.6) than in non-Hispanic (0.3±0.5) (p=0.0005), as well as imaging evidence of joint damage (32% vs. 24%) (p=0.008). In the multivariate linear regression analysis, the number of active joints was significantly higher in Hispanics than in non-Hispanics (p=0.03), after adjusting for confounders (income, health insurance, JIA subtype, positive RF, positive anti-CCP, use of intra-articular steroids, oral steroids, IV steroids, DMARDs, and biologics).

Conclusion:

Hispanic patients with JIA had higher disease activity (determined by number of active joints and parent/subject pain score) than non-Hispanic patients, as well as higher disease severity (by imaging evidence of joint damage) and disability (by CHAQ). Since ethnicity influences disease activity, severity, and disability, different management and treatment plans should be planned accordingly.

To cite this abstract, please use the following information:
Pelajo, Christina F., Angeles-Han, Sheila, Prahalad, Sampath, Sgarlat, Caitlin M., Davis, Trevor, Miller, Laurie C., et al; Evaluation of the Association Between Ethnicity and Disease Activity and Severity in a Large Cohort of Patients with Juvenile Idiopathic Arthritis. [abstract]. Arthritis Rheum 2011;63 Suppl 10 :293
DOI:

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