Sygdomsopblussen blev defineret som en ≥30% forværring af tre af seks JRA kernekriterier og ≥30% forbedring i højst en af seks JRA kernekriterier, og et minimum af to aktive led.
Disease flare was defined as a  30% worsening in three of six JRA core set criteria and  30% improvement in not more than one of the six JRA core set criteria and a minimum of two active joints.