Validation of the parent global assessment as a health-related quality of life measure in juvenile idiopathic arthritis: results from ReACCh-Out.

OBJECTIVES: To (i) validate the JIA parent global assessment (parent global) as a health-related quality of life (HRQoL) instrument; (ii) evaluate measurement properties of accepted HRQoL measures relative to those of the parent global; and (iii) assess causal pathways determining parent global scores. METHODS: Data from the Research in Arthritis in Canadian Children emphasizing outcomes (ReACCh-Out) cohort were used. Measurement properties were assessed in 344 patients at enrolment and 6 months later. Causal pathways were tested by structural equation modelling to understand root causes and mediators leading to parent global scores. RESULTS: Construct validity was supported by Spearman correlations of 0.53-0.70 for the parent global with the Juvenile Arthritis Quality of Life Questionnaire, Quality of My Life health scale (HRQoML), Pediatric Quality of Life Inventory (PedsQL)-Parent, and Child Health Questionnaire (CHQ)-Physical. Exceptions were PedsQL-Child (0.44) and CHQ-Psychosocial (0.31). Correlations were lower (0.14-0.49) with disease activity measures (physician global assessment of disease activity, active joint count, ESR). Responsiveness of the parent global to improvement according to parent ratings (0.51) was acceptable and within the range (0.32-0.71) of that of other measures. Reliability estimates and measurement errors for all measures were unsatisfactory, likely due to the prolonged time between assessments. Causal pathways for the parent global matched those previously reported for HRQoML. CONCLUSIONS: Our results offer support for the parent global as a valid measure of HRQoL for JIA. If confirmed, existing studies using the parent global may be re-interpreted, enhancing our knowledge of HRQoL in children with JIA.

A decade of progress in juvenile idiopathic athritis treatments and outcomes in Canada: results from ReACCh-Out and the CAPRI registry.

OBJECTIVE: To assess changes in juvenile idiopathic arthritis (JIA) treatments and outcomes in Canada, comparing a 2005-2010 and a 2017-2021 inception cohorts. METHODS: Patients enrolled within three months of diagnosis in the Research in Arthritis in Canadian Children Emphasizing Outcomes (ReACCh-Out) and the Canadian Alliance of Pediatric Rheumatology Investigators Registry (CAPRI) cohorts were included. Cumulative incidences of drug starts and outcome attainment within 70 weeks of diagnosis were compared with Kaplan Meier survival analysis and multivariable Cox regression. RESULTS: The 2005-2010 and 2017-2021 cohorts included 1128 and 721 patients, respectively. JIA category distribution and baseline clinical juvenile idiopathic arthritis disease activity (cJADAS10) scores at enrolment were comparable. By 70 weeks, 6% of patients (95% CI 5, 7) in the 2005-2010 and 26% (23, 30) in the 2017-2021 cohort had started a biologic DMARD (bDMARD), and 43% (40, 47) and 60% (56, 64) had started a conventional DMARD (cDMARD), respectively. Outcome attainment was 64% (61, 67) and 83% (80, 86) for Inactive disease (Wallace criteria), 69% (66, 72) and 84% (81, 87) for minimally active disease (cJADAS10 criteria), 57% (54, 61) and 63% (59, 68) for pain control (<1/10), and 52% (47, 56) and 54% (48, 60) for a good health-related quality of life. CONCLUSION: Although baseline disease characteristics were comparable in the 2005-2010 and 2017-2021 cohorts, cDMARD and bDMARD use increased with a concurrent increase in minimally active and inactive disease. Improvements in parent and patient reported outcomes were smaller than improvements in disease activity.

Causal pathways to health-related quality of life in children with juvenile idiopathic arthritis: results from the ReACCh-Out cohort.

OBJECTIVE: Structural equation modelling was applied to data from the Research in Arthritis in Canadian Children emphasizing Outcomes (ReACCh-Out) cohort to help elucidate causal pathways to decreased health-related quality of life (HRQoL) in children with JIA. METHODS: Based on published literature and clinical plausibility, a priori models were constructed with explicit root causes (disease activity, treatment intensity) and mediators (pain, disease symptoms, functional impairments) leading to HRQoL [measured by the Quality of my Life (QoML) scale and the Juvenile Arthritis Quality of Life Questionnaire (JAQQ)] at five disease stages: (i) diagnosis, (ii) 3-9 months after diagnosis, (iii) flare, (iv) remission on medications, (v) remission off medications. Following structural equation modelling, a posteriori models were selected based on data fit and clinical plausibility. RESULTS: We included 561, 887, 137, 186 and 182 patients at each stage, respectively. In a posteriori models for active disease stages, paths from disease activity led through pain, functional impairments, and disease symptoms, directly or through restrictions in participation, to decreased QoML scores. Treatment intensity had detrimental effects through psychosocial domains; while treatment side effects had a lesser role. Pathways were similar for QoML and JAQQ, but JAQQ models provided greater specificity. Models for remission stages were not supported by the data. CONCLUSION: Our findings support disease activity and treatment intensity as being root causes of decreased HRQoL in children with JIA, with pain, functional impairments, and participation restrictions being mediators for disease activity; they support psychosocial effects and side effects as being mediators for treatment intensity.

Associations of clinical and inflammatory biomarker clusters with juvenile idiopathic arthritis categories.

OBJECTIVE: To identify discrete clusters comprising clinical features and inflammatory biomarkers in children with JIA and to determine cluster alignment with JIA categories. METHODS: A Canadian prospective inception cohort comprising 150 children with JIA was evaluated at baseline (visit 1) and after six months (visit 2). Data included clinical manifestations and inflammation-related biomarkers. Probabilistic principal component analysis identified sets of composite variables, or principal components, from 191 original variables. To discern new clinical-biomarker clusters (clusters), Gaussian mixture models were fit to the data. Newly-defined clusters and JIA categories were compared. Agreement between the two was assessed using Kruskal-Wallis analyses and contingency plots. RESULTS: Three principal components recovered 35% (three clusters) and 40% (five clusters) of the variance in patient profiles in visits 1 and 2, respectively. None of the clusters aligned precisely with any of the seven JIA categories but rather spanned multiple categories. Results demonstrated that the newly defined clinical-biomarker lustres are more homogeneous than JIA categories. CONCLUSION: Applying unsupervised data mining to clinical and inflammatory biomarker data discerns discrete clusters that intersect multiple JIA categories. Results suggest that certain groups of patients within different JIA categories are more aligned pathobiologically than their separate clinical categorizations suggest. Applying data mining analyses to complex datasets can generate insights into JIA pathogenesis and could contribute to biologically based refinements in JIA classification.

Clinical and associated inflammatory biomarker features predictive of short-term outcomes in non-systemic juvenile idiopathic arthritis.

OBJECTIVE: To identify early predictors of disease activity at 18 months in JIA using clinical and biomarker profiling. METHODS: Clinical and biomarker data were collected at JIA diagnosis in a prospective longitudinal inception cohort of 82 children with non-systemic JIA, and their ability to predict an active joint count of 0, a physician global assessment of disease activity of ≤1 cm, and inactive disease by Wallace 2004 criteria 18 months later was assessed. Correlation-based feature selection and ReliefF were used to shortlist predictors and random forest models were trained to predict outcomes. RESULTS: From the original 112 features, 13 effectively predicted 18-month outcomes. They included age, number of active/effused joints, wrist, ankle and/or knee involvement, ESR, ANA positivity and plasma levels of five inflammatory biomarkers (IL-10, IL-17, IL-12p70, soluble low-density lipoprotein receptor-related protein 1 and vitamin D), at enrolment. The clinical plus biomarker panel predicted active joint count = 0, physician global assessment ≤ 1, and inactive disease after 18 months with 0.79, 0.80 and 0.83 accuracy and 0.84, 0.83, 0.88 area under the curve, respectively. Using clinical features alone resulted in 0.75, 0.72 and 0.80 accuracy, and area under the curve values of 0.81, 0.78 and 0.83, respectively. CONCLUSION: A panel of five plasma biomarkers combined with clinical features at the time of diagnosis more accurately predicted short-term disease activity in JIA than clinical characteristics alone. If validated in external cohorts, such a panel may guide more rationally conceived, biologically based, personalized treatment strategies in early JIA.

Teens Taking Charge: A Randomized Controlled Trial of a Web-Based Self-Management Program With Telephone Support for Adolescents With Juvenile Idiopathic Arthritis.

BACKGROUND: Juvenile idiopathic arthritis (JIA) is a serious and potentially debilitating pediatric illness. Improved disease self-management may help to improve health outcomes. OBJECTIVE: This study aimed to evaluate the effectiveness of the Teens Taking Charge Web-based self-management intervention in reducing symptoms and improving health-related quality of life (HRQL) in adolescents with JIA compared with a Web-based education control condition. METHODS: Adolescents with JIA aged 12 to 18 years were recruited from 11 Canadian pediatric rheumatology centers. Caregivers were invited to participate along with their child. In addition to standard medical care, participants were randomized to receive either (1) the Teens Taking Charge self-management intervention or (2) a Web-based education control condition for a period of 12 weeks. Adolescents in the intervention group completed website modules addressing cognitive behavioral coping skills, stress management, and other self-management topics, while also receiving monthly telephone calls from a trained health coach. Adolescents in the education control group were instructed to view a series of preselected public JIA educational websites and received monthly calls from a coach who asked about their own best efforts at managing JIA. Caregivers in the intervention group completed website modules related to promoting independence and disease self-management in their child. Caregivers in the education control group were instructed to view a series of preselected public JIA educational websites. Outcome assessment occurred at baseline, 12 weeks (posttreatment), and at 6 and 12 months postrandomization. The primary outcomes were pain intensity, pain interference, and HRQL. Secondary outcomes were emotional symptoms, adherence, coping, knowledge, and self-efficacy. RESULTS: In total, 333 adolescents and 306 caregivers were enrolled. Significant overall reductions in pain intensity (P=.02) and pain interference (P=.007) were observed for intervention group participants compared with those in the education control group, after adjusting for baseline levels. There was a significant overall improvement in HRQL related to problems with pain (P=.02) and problems with daily activities (P=.01). There was also a significant difference in the intervention group over time (P=.008) for HRQL related to treatment problems, with the intervention group participants demonstrating improved HRQL by 12 months compared with education control group participants. Both groups showed nonsignificant improvements compared with baseline in other primary outcomes. There were no significant differences between the groups in any secondary outcomes or caregiver-reported outcomes. CONCLUSIONS: The results of this randomized trial suggest that the Teens Taking Charge Web-based intervention is effective at reducing both pain intensity and pain interference, as well as improving HRQL in adolescents with JIA, compared with education control. These effects are sustained for up to 12 months following program completion. The Teens Taking Charge program is now publicly available at no cost. TRIAL REGISTRATION: ClinicalTrials.gov NCT01572896; https://clinicaltrials.gov/ct2/show/NCT01572896.

Predicting disease severity and remission in juvenile idiopathic arthritis: are we getting closer?

PURPOSE OF REVIEW: To summarize current research on the prediction of severe disease or remission in children with juvenile arthritis, and define further steps needed towards developing prediction tools with sufficient accuracy for clinical use. RECENT FINDINGS: High disease activity, poor patient-reported outcomes, ankle or wrist involvement, and a longer time from onset to the start of treatment herald a severe disease course and a low chance of remission. Other studies confirmed that age less than 7 years and positive ANA are the strongest predictors of uveitis development. Preliminary evidence suggests ultrasound findings may predict flare in patients with clinically inactive disease, and several new biomarkers show promise. A few prediction tools that combine predictors to estimate the chance of remission or a severe disease course in the medium-term to long-term have shown good accuracy when internally validated in the population in which they were developed. SUMMARY: Promising candidate tools for predicting disease severity and long-term remission in juvenile arthritis are now available. These tools need external validation in other populations, and ideally formal trials to assess whether their use in practice improves patient outcomes. We are definitively getting closer, but we are not there yet.

Validation of administrative case ascertainment algorithms for chronic childhood arthritis in Manitoba, Canada.

We validated case ascertainment algorithms for juvenile idiopathic arthritis (JIA) in the provincial health administrative databases of Manitoba, Canada. A population-based pediatric rheumatology clinical database from April 1st 1980 to March 31st 2012 was used to test case definitions in individuals diagnosed at ≤15 years of age. The case definitions varied the number of diagnosis codes (1, 2, or 3), time frame (1, 2 or 3 years), time between diagnoses (ever, >1 day, or ≥8 weeks), and physician specialty. Positive predictive value (PPV), sensitivity, and specificity with 95% confidence intervals (CIs) are reported. A case definition of 1 hospitalization or ≥2 diagnoses in 2 years by any provider ≥8 weeks apart using diagnosis codes for rheumatoid arthritis and ankylosing spondylitis produced a sensitivity of 89.2% (95% CI 86.8, 91.6), specificity of 86.3% (95% CI 83.0, 89.6), and PPV of 90.6% (95% CI 88.3, 92.9) when seronegative enthesopathy and arthropathy (SEA) was excluded as JIA; and sensitivity of 88.2% (95% CI 85.7, 90.7), specificity of 90.4% (95% CI 87.5, 93.3), and PPV of 93.9% (95% CI 92.0, 95.8) when SEA was included as JIA. This study validates case ascertainment algorithms for JIA in Canadian administrative health data using diagnosis codes for both rheumatoid arthritis (RA) and ankylosing spondylitis, to better reflect current JIA classification than codes for RA alone. Researchers will be able to use these results to define cohorts for population-based studies.

The risk and nature of flares in juvenile idiopathic arthritis: results from the ReACCh-Out cohort.

OBJECTIVE: To describe probabilities and characteristics of disease flares in children with juvenile idiopathic arthritis (JIA) and to identify clinical features associated with an increased risk of flare. METHODS: We studied children in the Research in Arthritis in Canadian Children emphasizing Outcomes (ReACCh-Out) prospective inception cohort. A flare was defined as a recurrence of disease manifestations after attaining inactive disease and was called significant if it required intensification of treatment. Probability of first flare was calculated with Kaplan-Meier methods, and associated features were identified using Cox regression. RESULTS: 1146 children were followed up a median of 24 months after attaining inactive disease. We observed 627 first flares (54.7% of patients) with median active joint count of 1, physician global assessment (PGA) of 12 mm and duration of 27 weeks. Within a year after attaining inactive disease, the probability of flare was 42.5% (95% CI 39% to 46%) for any flare and 26.6% (24% to 30%) for a significant flare. Within a year after stopping treatment, it was 31.7% (28% to 36%) and 25.0% (21% to 29%), respectively. A maximum PGA >30 mm, maximum active joint count >4, rheumatoid factor (RF)-positive polyarthritis, antinuclear antibodies (ANA) and receiving disease-modifying antirheumatic drugs (DMARDs) or biological agents before attaining inactive disease were associated with increased risk of flare. Systemic JIA was associated with the lowest risk of flare. CONCLUSIONS: In this real-practice JIA cohort, flares were frequent, usually involved a few swollen joints for an average of 6 months and 60% led to treatment intensification. Children with a severe disease course had an increased risk of flare.

The outcomes of juvenile idiopathic arthritis in children managed with contemporary treatments: results from the ReACCh-Out cohort.

OBJECTIVE: To describe clinical outcomes of juvenile idiopathic arthritis (JIA) in a prospective inception cohort of children managed with contemporary treatments. METHODS: Children newly diagnosed with JIA at 16 Canadian paediatric rheumatology centres from 2005 to 2010 were included. Kaplan-Meier survival curves for each JIA category were used to estimate probability of ever attaining an active joint count of 0, inactive disease (no active joints, no extraarticular manifestations and a physician global assessment of disease activity <10 mm), disease remission (inactive disease >12 months after discontinuing treatment) and of receiving specific treatments. RESULTS: In a cohort of 1104 children, the probabilities of attaining an active joint count of 0 exceeded 78% within 2 years in all JIA categories. The probability of attaining inactive disease exceeded 70% within 2 years in all categories, except for RF-positive polyarthritis (48%). The probability of discontinuing treatment at least once was 67% within 5 years. The probability of attaining remission within 5 years was 46-57% across JIA categories except for polyarthritis (0% RF-positive, 14% RF-negative). Initial treatment included joint injections and non-steroidal anti-inflammatory drugs for oligoarthritis, disease-modifying antirheumatic drugs (DMARDs) for polyarthritis and systemic corticosteroids for systemic JIA. CONCLUSIONS: Most children with JIA managed with contemporary treatments attain inactive disease within 2 years of diagnosis and many are able to discontinue treatment. The probability of attaining remission within 5 years of diagnosis is about 50%, except for children with polyarthritis.

Chronic inflammatory arthritis prevalence estimates for children and adolescents in three Canadian provinces.

There is a paucity of published population-based estimates of the prevalence of chronic inflammatory arthritis in the pediatric population. We used administrative health data to estimate the prevalence of chronic inflammatory arthritis in individuals ≤18 years in three Canadian provinces: Quebec, Manitoba, and Saskatchewan. Cases aged ≤18 years were identified by meeting any one of the following criteria: (a) ≥1 hospital discharge abstract with an ICD-9 code of 714 or ICD-10-CA codes of M05, M06 or M08, or (b) ≥2 ICD-9 714 billing codes ≥8 weeks apart, but within 2 years, or (c) ≥1 ICD-9 714 billing code by a rheumatologist. Crude prevalence estimates per 10,000 population were estimated with 95 % confidence intervals (CIs). Prevalence estimates were 11.7 per 10,000 individuals ≤18 years of age in Manitoba, 9.8 per 10,000 in Saskatchewan, and 8.0 per 10,000 in Quebec. In pairwise comparisons of rate differences, Manitoba and Saskatchewan had higher estimates than Quebec. Prevalence estimates were higher for females than males, with a difference of 5.9 cases per 10,000 residents (95 % CI 5.1, 6.7). Saskatchewan was the only province with a higher estimate in urban compared to rural residents (5.2, 95 % CI 2.5, 8.0). Variations in provincial estimates may be due to differences in underlying population characteristics. Although these estimates have face validity and are in keeping with the range of previously published pediatric prevalence estimates, studies to establish the empiric validity of case-finding algorithms are needed to advance research in pediatric chronic disease epidemiology.

A Comparison of International League of Associations for Rheumatology and Pediatric Rheumatology International Trials Organization Classification Systems for Juvenile Idiopathic Arthritis Among Children in a Canadian Arthritis Cohort.

OBJECTIVE: The aim of the Paediatric Rheumatology International Trials Organisation (PRINTO) juvenile idiopathic arthritis (JIA) classification criteria, which is still in development, is to identify homogeneous groups of JIA patients. This study was undertaken to compare International League of Associations for Rheumatology (ILAR) JIA classification criteria and PRINTO JIA classification criteria using data from the ReACCh-Out (Research in Arthritis in Canadian Children, Emphasizing Outcomes) cohort. METHODS: We used clinicobiologic data recorded within 7 months of diagnosis to assign a diagnosis of JIA and identify subcategories of JIA among 1,228 patients according to the 2 JIA classification systems. We compared the proportions of patients classified and the alignment of classification categories with clinicobiologic subtypes and adult arthritis types. RESULTS: The PRINTO criteria classified 244 patients (19.9%) as having early-onset antinuclear antibody-positive JIA, 157 (12.8%) as having enthesitis/spondylitis-related JIA, 38 (3.1%) as having systemic JIA, and 10 (0.8%) as having rheumatoid factor-positive JIA. A total of 12% of patients were unclassifiable using the ILAR criteria, while 63.3% were unclassifiable using the PRINTO criteria (777 with other JIA and 2 with unclassified JIA). In sensitivity analyses, >50% of patients remained unclassifiable using the PRINTO criteria. Compared to the PRINTO criteria, ILAR JIA categories aligned better with clinicobiologic subtypes in 131 patients (χ2 = 44, P = 0.005, versus χ2 = 15, P = 0.07 for PRINTO), and ILAR categories aligned better with adult types of arthritis in 389 evaluable patients. CONCLUSION: Currently identified PRINTO disorders can only be used to classify a minority of JIA patients, leaving a large proportion of JIA patients with other disorders requiring further characterization. Current PRINTO JIA classification criteria do not align better with clinicobiologic subtypes or adult forms of arthritis compared with the older ILAR classification system.

Higher concentrations of vitamin D in Canadian children with juvenile idiopathic arthritis compared to healthy controls are associated with more frequent use of vitamin D supplements and season of birth.

A number of studies have demonstrated that patients with autoimmune disease have lower levels of vitamin D prompting speculation that vitamin D might suppress inflammation and immune responses in children with juvenile idiopathic arthritis (JIA).  The objective of this study was to compare vitamin D levels in children with JIA at disease onset with healthy children. We hypothesized that children and adolescents with JIA have lower vitamin D levels than healthy children and adolescents. Data from a Canadian cohort of children with new-onset JIA (n= 164, data collection 2007-2012) were compared to Canadian Health Measures Survey (CHMS) data (n=4027, data collection 2007-2011). We compared 25-hydroxy vitamin D (25(OH)D) concentrations with measures of inflammation, vitamin D supplement use, milk intake, and season of birth. Mean 25(OH)D level was significantly higher in patients with JIA (79 ± 3.1 nmol/L) than in healthy controls (68 ± 1.8 nmol/L P <.05). Patients with JIA more often used vitamin D containing supplements (50% vs. 7%; P <.05). The prevalence of 25(OH)D deficiency (<30 nmol/L) was 6% for both groups. Children with JIA with 25(OH)D deficiency or insufficiency (<50 nmol/L) had higher C-reactive protein levels. Children with JIA were more often born in the fall and winter compared to healthy children. In contrast to earlier studies, we found vitamin D levels in Canadian children with JIA were higher compared to healthy children and associated with more frequent use of vitamin D supplements. Among children with JIA, low vitamin D levels were associated with indicators of greater inflammation.

Soluble Low-density Lipoprotein Receptor-related Protein 1 in Juvenile Idiopathic Arthritis.

OBJECTIVES: This study aimed to expand knowledge about soluble low-density lipoprotein receptor-related protein 1 (sLRP1) in juvenile idiopathic arthritis (JIA) by determining associations of sLRP1 levels in nonsystemic JIA patients with clinical and inflammatory biomarker indicators of disease activity. METHODS: Plasma sLRP1 and 44 inflammation-related biomarkers were measured at enrollment and 6 months later in a cohort of 96 newly diagnosed Canadian patients with nonsystemic JIA. Relationships between sLRP1 levels and indicators of disease activity and biomarker levels were analyzed at both visits. RESULTS: At enrollment, sLRP1 levels correlated negatively with age and active joint counts. Children showed significantly higher levels of sLRP1 than adolescents (mean ranks: 55.4 and 41.9, respectively; P = 0.02). Participants with 4 or fewer active joints, compared to those with 5 or more active joints, had significantly higher sLRP1 levels (mean ranks: 56.2 and 40.7, respectively; P = 0.006). At enrollment, considering the entire cohort, sLRP1 correlated negatively with the number of active joints (r = -0.235, P = 0.017). In the entire cohort, sLRP1 levels at enrollment and 6 months later correlated with 13 and 6 pro- and antiinflammatory biomarkers, respectively. In JIA categories, sLRP1 correlations with inflammatory markers were significant in rheumatoid factor-negative polyarticular JIA, oligoarticular JIA, enthesitis-related arthritis, and psoriatic arthritis at enrollment. Higher sLRP1 levels at enrollment increased the likelihood of absence of active joints 6 months later. CONCLUSION: Plasma sLRP1 levels correlate with clinical and biomarker indicators of short-term improvement in JIA disease activity, supporting sLRP1 as an upstream biomarker of potential utility for assessing JIA disease activity and outcome prediction.

Clinical and psychosocial stress factors are associated with decline in physical activity over time in children with juvenile idiopathic arthritis.

BACKGROUND: Physical activity (PA) patterns in children with juvenile idiopathic arthritis (JIA) over time are not well described. The aim of this study was to describe associations of physical activity (PA) with disease activity, function, pain, and psychosocial stress in the 2 years following diagnosis in an inception cohort of children with juvenile idiopathic arthritis (JIA). METHODS: In 82 children with newly diagnosed JIA, PA levels, prospectively determined at enrollment, 12 and 24 months using the Physical Activity Questionnaire for Children (PAQ-C) and Adolescents (PAQ-A) raw scores, were evaluated in relation to disease activity as reflected by arthritis activity (Juvenile Arthritis Disease Activity Score (JADAS-71)), function, pain, and psychosocial stresses using a linear mixed model approach. Results in the JIA cohort were compared to normative Pediatric Bone Mineral Accrual Study data derived from healthy children using z-scores. RESULTS: At enrollment, PA z-score levels of study participants were lower than those in the normative population (median z-score - 0.356; p = 0.005). At enrollment, PA raw scores were negatively associated with the psychosocial domain of the Juvenile Arthritis Quality of Life Questionnaire (r = - 0.251; p = 0.023). There was a significant decline in PAQ-C/A raw scores from baseline (median and IQR: 2.6, 1.4-3.1) to 24 months (median and IQR: 2.1, 1.4-2.7; p = 0.003). The linear mixed-effect model showed that PAQ-C/A raw scores in children with JIA decreased as age, disease duration, and ESR increased. The PAQ-C/A raw scores of the participants was also negatively influenced by an increase in disease activity as measured by the JADAS-71 (p <  0.001). CONCLUSION: Canadian children with newly diagnosed JIA have lower PA levels than healthy children. The decline in PA levels over time was associated with disease activity and higher disease-specific psychosocial stress.

Real-World Effectiveness of Common Treatment Strategies for Juvenile Idiopathic Arthritis: Results From a Canadian Cohort.

OBJECTIVE: Undervaluing the effectiveness of conventional treatments may lead to overtreatment with biologic medications in children with juvenile idiopathic arthritis (JIA). Using data from a nationwide inception cohort and strict methods to control bias, the aim of our study was to estimate the real-world effectiveness of simple JIA treatment strategies recommended in current guidelines. METHODS: Children with JIA who were recruited at 16 Canadian centers from 2005 to 2010 were followed for up to 5 years. For each child, all observed treatment changes over time were assessed by independent physicians using prospectively collected data and published response criteria. Success was defined as attainment of inactive disease or maintenance of this state when stepping down treatment; minimally active disease was deemed acceptable for children with polyarticular JIA. Success rates were calculated for treatments tried ≥25 times, and logistic regression analysis identified features associated with success. RESULTS: A total of 4,429 treatment episodes were observed in 1,352 children. Nonsteroidal antiinflammatory drug (NSAID) monotherapy was attempted 697 times, mostly as initial treatment when <5 joints were involved, with a 54.4% success rate (95% confidence interval [95% CI] 50.3-58.6). NSAIDs plus joint injections had a 64.7% success rate (95% CI 59.8-69.7). Adding methotrexate to NSAIDs and/or joint injections (attempted 566 times) had a 60.5% success rate (95% CI 55.7-65.3). In adjusted analyses, each additional active joint reduced chances of success for treatment with NSAIDs (odds ratio [OR] 0.90 [95% CI 0.85-0.94]) and for methotrexate combinations (OR 0.96 [95% CI 0.94-0.99]). Each additional year after disease onset reduced chances of success for treatment with methotrexate combinations (OR 0.83 [95% CI 0.72-0.95]). CONCLUSION: These real-world effectiveness estimates show that conventional nonbiologic treatment strategies that are recommended in current guidelines are effective in achieving treatment targets in many children with JIA.

Trends in Population-Based Incidence and Prevalence of Juvenile Idiopathic Arthritis in Manitoba, Canada.

OBJECTIVE: To estimate the incidence and prevalence of juvenile idiopathic arthritis (JIA) in children ages <16 years in the province of Manitoba, Canada, and to determine changes in estimates between 2000 and 2012. METHODS: JIA cases were ascertained from the administrative health data of Manitoba, using a validated case-finding algorithm. Annual incidence and prevalence rates were estimated using a generalized linear model with generalized estimating equations (GEEs), adjusting for sociodemographic characteristics. Changes in estimates were tested using piecewise regression models. RESULTS: A total of 455 cases of JIA prevalence met the inclusion criteria. Sex- and age-adjusted incidence estimates were 14.01 (95% confidence interval [95% CI] 13.52, 14.53) in 2000/2001 and 9.18 (95% CI 8.56, 9.85) in 2010/2011. Prevalence estimates were 65.33 (95% CI 63.87, 66.83) in 2000/2001 and 59.61 (95% CI 58.17, 61.08) in 2010/2011. A linear piecewise model provided the best fit to the data. There was a significant decrease in prevalence over the study period (-0.18 [95% CI -0.35, -0.02]; P = 0.0292) but no statistically significant change in incidence (-0.46 [95% CI -0.94, 0.01]; P = 0.0571). Sex-stratified models revealed a decrease for males in both prevalence (estimate -0.54 [95% CI -0.84, -10.25]; P = 0.0003) and incidence (estimate -1.02 [95% CI -2.02, -0.04]; P = 0.0439); there were no changes for females. CONCLUSION: Few population-based longitudinal epidemiologic studies of JIA have been conducted. Our findings suggested a decrease in overall JIA prevalence, and in incidence and prevalence in men. Further research to validate these findings in other cohorts and to explore factors that contribute to this change will benefit future health care planning for JIA.

Prospective Determination of the Incidence and Risk Factors of New-Onset Uveitis in Juvenile Idiopathic Arthritis: The Research in Arthritis in Canadian Children Emphasizing Outcomes Cohort.

OBJECTIVE: Identification of the incidence of juvenile idiopathic arthritis (JIA)-associated uveitis and its risk factors is essential to optimize early detection. Data from the Research in Arthritis in Canadian Children Emphasizing Outcomes inception cohort were used to estimate the annual incidence of new-onset uveitis following JIA diagnosis and to identify associated risk factors. METHODS: Data were reported every 6 months for 2 years, then yearly to 5 years. Incidence was determined by Kaplan-Meier estimators with time of JIA diagnosis as the reference point. Univariate log-rank analysis identified risk factors and Cox regression determined independent predictors. RESULTS: In total, 1,183 patients who enrolled within 6 months of JIA diagnosis met inclusion criteria, median age at diagnosis of 9.0 years (interquartile range [IQR] 3.8-12.9), median follow-up of 35.2 months (IQR 22.7-48.3). Of these patients, 87 developed uveitis after enrollment. The incidence of new-onset uveitis was 2.8% per year (95% confidence interval [95% CI] 2.0-3.5) in the first 5 years. The annual incidence decreased during follow-up but remained at 2.1% (95% CI 0-4.5) in the fifth year, although confidence intervals overlapped. Uveitis was associated with young age (<7 years) at JIA diagnosis (hazard ratio [HR] 8.29, P < 0.001), positive antinuclear antibody (ANA) test (HR 3.20, P < 0.001), oligoarthritis (HR 2.45, P = 0.002), polyarthritis rheumatoid factor negative (HR 1.65, P = 0.002), and female sex (HR 1.80, P = 0.02). In multivariable analysis, only young age at JIA diagnosis and ANA positivity were independent predictors of uveitis. CONCLUSION: Vigilant uveitis screening should continue for at least 5 years after JIA diagnosis, and priority for screening should be placed on young age (<7 years) at JIA diagnosis and a positive ANA test.

Predicting Which Children with Juvenile Idiopathic Arthritis Will Not Attain Early Remission with Conventional Treatment: Results from the ReACCh-Out Cohort.

OBJECTIVE: To estimate the probability of early remission with conventional treatment for each child with juvenile idiopathic arthritis (JIA). Children with a low chance of remission may be candidates for initial treatment with biologics or triple disease-modifying antirheumatic drugs (DMARD). METHODS: We used data from 1074 subjects in the Research in Arthritis in Canadian Children emphasizing Outcomes (ReACCh-Out) cohort. The predicted outcome was clinically inactive disease for ≥ 6 months starting within 1 year of JIA diagnosis in patients who did not receive early biologic agents or triple DMARD. Models were developed in 200 random splits of 75% of the cohort and tested on the remaining 25% of subjects, calculating expected and observed frequencies of remission and c-index values. RESULTS: Our best Cox logistic model combining 18 clinical variables a median of 2 days after diagnosis had a c-index of 0.69 (95% CI 0.67-0.71), better than using JIA category alone (0.59, 95% CI 0.56-0.63). Children in the lowest probability decile had a 20% chance of remission and 21% attained remission; children in the highest decile had a 69% chance of remission and 73% attained remission. Compared to 5% of subjects identified by JIA category alone, the model identified 14% of subjects as low chance of remission (probability < 0.25), of whom 77% failed to attain remission. CONCLUSION: Although the model did not meet our a priori performance threshold (c-index > 0.70), it identified 3 times more subjects with low chance of remission than did JIA category alone, and it may serve as a benchmark for assessing value added by future laboratory/imaging biomarkers.

Health-Related Quality of Life in an Inception Cohort of Children With Juvenile Idiopathic Arthritis: A Longitudinal Analysis.

OBJECTIVE: To describe changes in health-related quality of life (HRQoL) over time in children with juvenile idiopathic arthritis (JIA), relative to other outcomes, and to identify predictors of unfavorable HRQoL trajectories. METHODS: Children with JIA in the Research in Arthritis in Canadian Children emphasizing Outcomes (ReACCh-Out) cohort were included. The Juvenile Arthritis Quality of Life Questionnaire (JAQQ, a standardized instrument), health-related Quality of My Life (HRQoML, an instrument based on personal valuations), and JIA core variables were completed serially. Analyses included median values, Kaplan-Meier survival curves, and latent trajectory analysis. RESULTS: A total of 1,249 patients enrolled at a median of 0.5 months after diagnosis were followed for a median of 34.2 months. The degree of initial HRQoL impairment and probabilities of reaching the best possible HRQoL scores varied across JIA categories (best for oligoarthritis, worst for rheumatoid factor-positive polyarthritis). Median times to attain best possible HRQoL scores (JAQQ 59.3 months, HRQoML 34.5 months), lagged behind those for disease activity, pain, and disability measures. Most patients followed trajectories with minimal or mild impairment; however, 7.6% and 13.8% of patients, respectively, followed JAQQ and HRQoML trajectories with persistent major impairment in HRQoL. JIA category, aboriginal ethnicity, and baseline disease activity measures distinguished between membership in trajectories with major and minimal impairments. CONCLUSION: Improvement in HRQoL is slower than for disease activity, pain, and disability. Improvement of a measure based on respondents' preferences (HRQoML) is more rapid than that of a standardized measure (JAQQ). Higher disease activity at diagnosis heralds an unfavorable HRQoL trajectory.