What we can learn from existing evidence about physical activity for juvenile idiopathic arthritis?

Abstract

The need for more rigorously designed trials to optimize the implementation of physical activity programmes Juvenile idiopathic arthritis (JIA) is one of the most common chronic conditions of childhood. Existing clinical practice guidelines (CPGs) for JIA illustrate the importance of care using both pharmacological and non-pharmacological interventions [1]. To date, however, CPGs including non-pharmacological interventions, such as physical activity (PA), have not been as rigorously developed as those for pharmacological interventions [1]. A recent systematic review on high-quality randomized controlled trials (RCTs) [2] revealed that a wide variety of structured PA programmes (i.e. cardio-karate [3], aquatics [4], pilates [5] and strength training [6,7]) are effective self-management therapy options for individuals with JIA. In comparison with a control, these PA programmes combined with pharmacotherapy have been shown to produce numerous positive health outcomes, such as reducing the number of actively inflamed joints (decrease in swollen and tender joint count) [3,4] and pain intensity [5], as well as improving joint range of motion [3,5], muscle strength [6], functional status [5,7] and quality of life [5,7]. While it has been shown that these PA programmes are safe and effective for the management of JIA [2,8], there remains a significant knowledge gap in our understanding of how to optimize the dissemination of this knowledge for clinical application. The critical knowledge required to achieve this goal includes advancing our understanding of who would benefit most from PA interventions [i.e. target populations and JIA sub-types such as systemic arthritis, oligoarthritis, polyarthritis (rheumatoid factor negative), polyarthritis (rheumatoid factor positive)]; the optimal PA intervention parameters and comparators; the most appropriate outcome measures; and the ideal timing of the PA intervention. Future RCTs need to allow future PA CPGs targeting those with JIA to have the information required to facilitate informed decision making by health professionals as well as by the children and adolescents with JIA and their families. Study selection criteria should include the target population while considering specific factors or conditions associated with the disease, such as the JIA specific onset type and the degree of severity or chronicity of JIA (very young patients who have faced impaired or altered motor development might need different approaches compared with their relatively healthy counterparts with normal initial physical development). In addition , the number of active joints and their location (e.g. upper or lower extremities), the presence of comor-bidities, changes in medication during the intervention period [2], common contraindications to the proposed therapy, C1 to C2 vertebral instability or the presence of enthesitis or cardiac complications are also considered important criteria [8]. The description of the PA intervention used for JIA in future studies should also be more explicit [9] and key characteristics of the intervention [e.g. types of PA, PA dosage (volume, intensity, duration)] should be provided for potential users and for clinical and research replication purposes [9]. Despite the fact that there has been an increase in the number of studies examining the benefits of PA in the management of JIA in children and adolescents, there remains a paucity of information about which types of PA are best for supporting joint development and bone health in children [8]. Furthermore, it is unclear if other types of PA programmes, such as Tai Chi, Yoga and other active leisure activities, in general could elicit positive health outcomes similar to those identified above [2]. Other key questions which remain to be addressed include: What types of PA are most appealing and enjoyable for children and adolescents with JIA [2]? Would regular participation in a safe PA programme be sufficient to self-manage pain [2]? What is the required PA dose to achieve optimal musculoskeletal health and cardiorespiratory fitness for long-term global health [2]? In order to acquire the knowledge needed to define solid evidence-based clinical practice [2], future studies will need to consider the following: the selection of the most appropriate comparators or control groups in all RCTs examining the clinical effectiveness of PA in the management of JIA; the definition of reliable and valid outcome measures to evaluate the clinical effectiveness of the PA intervention for the target population [2]; and the determination of the optimal duration of the PA intervention and follow-up. Altogether, the results from well-designed RCTs will provide the crucial information that will enable the development of specific guidelines and recommendations for PA programmes in the management of JIA and will enable the provision of better advice for health-care professionals as well as for children, adolescents and their family members. For example, acquiring this knowledge will help address key questions such as: What are the optimal exercise intervention programmes that should be employed in the management of JIA? To