The PERSON-JIA Trial is a cluster-randomized trial testing the use of Shared Decision Making (SDM) with families for treatment of children with arthritis. The intervention is a discussion between physicians and families at the time of diagnosis that uses computer-generated personalized outcome reports generated by previously developed prediction algorithms. By using information provided by thousands of families, the investigators have developed a way of providing answers to common questions asked by patients and their families at diagnosis. We will test whether a structured discussion and shared decision between families and doctors (guided by the patient's personal report) will improve the tailoring of treatment to the child and control of their disease. The personal report is called the PERSON-JIA report and presents the child's expected disease severity, the likelihood the child will be arthritis free by age 18 and the chance treatments will be effective and/or have side effects. This way, answers to these questions can be shared by physicians and families to weigh potential benefits and harms according to family values and preferences. The investigators expect that using the personalized report in a frank and thoughtful discussion will help physicians and families make better decisions about managing the child's disease. This in turn will result in better disease control, greater family engagement and satisfaction with care and better-tailored treatment. If so, this will be a ground-breaking way of using information provided by families and doctors to improve the care provided to and the outcomes of children with arthritis in Canada.