Enhancing the precision of clinical assessment in juvenile idiopathic arthritis through the JADAS.

The use of composite disease activity scores enables a pragmatic approach to the measurement of the level of disease activity in children with juvenile idiopathic arthritis (JIA). These tools are constructed through the combination of individual measures and provide a quantification of the absolute level of disease activity in one summary number on a continuous scale. The first composite score for JIA, named Juvenile Arthritis Disease Activity Score (JADAS), was published in 2009. It includes the following four variables: physician global assessment, parent/patient global assessment, active joints count, and an acute phase reactant. Its score is calculated as the arithmetic sum of the scores of its four items. Additional versions of the JADAS, which lack the acute phase reactant (clinical JADAS, cJADAS) or are specific to systemic JIA (systemic JADAS, sJADAS), were developed over the years. An important progress in the field has been represented by the definition of the cutoff values in the JADAS that distinguish the states of inactive disease or minimal, moderate, and high disease activity in JIA. These cutoffs may serve as therapeutic targets in the treat-to-target strategy. Recently, a JADAS version entirely composed of parent/patient-reported outcome measures has been developed and validated. This tool is well suited to implement remote patient monitoring, a form of telemedicine that may help to optimize disease control and reduce the pressure on healthcare systems. This review is aimed to describe the different versions of the JADAS and the main aspects of their developmental process.