Our search strategy identified 4,285 records (Fig. 1). Of those records 4,074 were deemed unique and were first reviewed by title and abstract to screen for inclusion criteria, such as being a Canadian RCT and participants having JIA. Studies that passed the initial screening were then reviewed by full text to ensure all studies adhered to the inclusion criteria. At this stage, emphasis was put on determining if Canada was the central site for the JIA RCTs, as many studies had Canadian locations, but few were centrally coordinated by Canadian researchers. Altogether, five studies were deemed eligible, and they ranged in sample size from 14 to 219 participants. From the eligible studies, one evaluated a pharmacological intervention, determining the impact of food on the bioavailability of oral methotrexate (n = 14) [15]. The other four studies evaluated non-pharmacological interventions, namely a smartphone-based pain management program (n = 60) [16], an online peer mentoring program (n = 30) [17], a web-based coping and stress management program (n = 219) [18], and the effectiveness of high-intensity aerobic training compared to low-intensity training on children with JIA (n = 80) [19] (Table 1).

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) diagram. JIA = Juvenile Idiopathic Arthritis; RCT = randomized controlled trial

We characterized participants of RCTs of JIA in Canada from studies that reported sex (all studies) and age (all studies). Participants were primarily female, comprising 70.3% [18] to 94% [17] of study populations. With respect to age, participants were mainly early adolescents. The average age of participants was 12.6 years, with a range of 8.39 to 15.0 years. Two studies included participants under 12 years old [15, 19], with the youngest being 2.8 years [15]. In the one study that reported on race, 70.2% of participants were White [16].

We also assessed how included studies reported PROGRESS-Plus factors (summarized in Table 1). Five of the factors - Place of residence, Occupation, Religion, Social Capital and Time-dependent relationships - were not reported in any study. Six factors - Personal Characteristics associated with discrimination, Race, Sex, Socioeconomic status, Education and Features of relationships - were reported but to a varying extent.

Personal characteristics associated with discrimination falls under the “Plus” category of the PROGRESS-Plus factors, and encompass characteristics such as age or disability that can be a cause of discrimination [9]. From the personal characteristics associated with discrimination, the only factor that was reported was age. Though we note that age may not be associated with discrimination in the pediatric demographic. All included studies reported participant ages, four using the mean and standard deviation in years [16,17,18,19] and one reporting the age of each participant in years individually [15]. Two studies reported the mean age of participants and controls separately [16, 17], and one study reported the range of ages as well [19].

Within the PROGRESS-Plus factors, the category of race, ethnicity, culture and language refer to the racial, ethnic and cultural background of individuals [9]. This is relevant as it has been historically shown that health outcomes differ when comparing patients across different races, ethnicities, and cultures. The three terms are often used interchangeably, however race refers to a biological quality while ethnicity and culture encompass social aspects [9, 20]. Although the category of race is controversial in nature due to its lack of basis on distinct genetic differences, it is important to note as most racial inequities are caused by the social experiences of “racialized groups” and may impact the inequities seen in healthcare [9]. Race was reported in a single study [16] with a limited diversity of race categories (Aboriginal, Arab or West Asian, Black, Chinese, Filipino, Multiracial, South Asian, South East Asian, and White) and no mention of the related factors of culture and ethnicity. Of note, an inclusion criterion for participation in this study was the ability to speak and read in English however there was no mention of native or additional languages. Most participants were White (70.2%), with the second largest group (10.5% of participants) being Multi-racial. No definition or description was given on what the criteria were to be considered “White” or “Multi-racial, such as place of birth or ancestry.

It is important to consider sex in health research as it results in variation in disease risk and incidence [9]. It is equally important to consider gender as it impacts an individual’s experience of the disease. An understanding of which populations require more personalized care would help improve disease outcomes and allow for better use of resources. As previously described in characterizing trial participants, sex was reported in all studies. When reporting, gender and sex terms were used interchangeably in two studies [15, 19], with both equating “boys” and “girls” (gender) to “male” and “female” (sex). These two studies were conducted between 1995 and 2007. All studies were limited to binary categories (male or female) with no gender or sex-diverse terms (such as gender non-binary or gender fluid).

Socioeconomic status (SES) encompasses income, educational attainment, and occupation (the latter two being independent PROGRESS-Plus factors) [21] and is a measure of an individual’s economic and social status in relation to others [22]. Average household income was reported in one study [18], ranging from <$25,000 CAD to between $100,000 and $150,000 CAD with an option not to report. Few (4.6%) participants fell in the <$25,000 CAD category, 12.7% in the $25,000 to $49,999 CAD, 14.2% in the $50,000 to $74,999 CAD, 16.8% in the $75,000 to $99,999 CAD, 16.8% in the $100,000 to $150,000 CAD, and 22.3% chose not to report. Given the younger age of JIA patients in these trials, an important consideration is who are questions related to income directed to – whether participants themselves or parents/guardians. It is likely that responses regarding household income was reported by parents and/or guardians.

Education is important to consider due to its long-term effects on socioeconomic status (specifically income). An individual’s level of education impacts their level of employment which is generally correlated with income, and those with higher education levels and incomes tend to live healthier lives and experience less financial burden [9]. However, this again, is of particular consideration for younger participants who are still attaining education. Participant education level was only mentioned in one study and was reported as the average current grade of the participants (Grade 9) [17].

Features of relationships refers to the characteristics of the external relationships of a patient that affect their ability to assert their autonomy over their health [23]. These relationships are important to consider as they help to provide context for patient treatment, especially for paediatric patients where parents/guardians hold primary responsibility for patient care. Features of relationships were mentioned in one study as the percentage of caregivers who had graduated from college or graduate school (65.5%) [18] .