Costello R, McDonagh J, Hyrich K, et al. - For the first time in 25 years, this study offered contemporaneous estimates of the occurrence of juvenile idiopathic arthritis (JIA) in the United Kingdom. Such estimates are critical for resource allocation and the development of health services for the management of JIA.

• Children and adolescents with JIA were found in the Clinical Practice Research Datalink GOLD and Aurum databases, which draw data from the UK's two most widely used primary care electronic health record systems.

• The age-standardised incidence rate was 5.61 per 100,000 population, whereas the age-standardised prevalence rate in 2018 was 43.5 per 100,000.

• Scotland had higher rates than England, with an incidence rate ratio of 1.27.

• Over a 5-year period, the incidence rates did not vary considerably.