Validation and adaptation of a German screening tool to identify patients at risk of juvenile idiopathic arthritis.

The primary objective was twofold: (1) to determine whether the German version of a screening instrument for clinical practice for juvenile idiopathic arthritis (SICJIA) is reliable in identifying patients at risk for juvenile idiopathic arthritis (JIA), and (2) secondly whether a weighting scheme of individual questions improves its sensitivity. Data were collected and retrospectively analyzed based upon completed SICJIA questionnaires from patients and their guardians at their first clinical visit at the Hamburg Centre for Pediatric and Adolescence Rheumatology. All patients visited the center between August 2015 and July 2017. The survey included 12 disease-orientated questions. For evaluation, only questionnaires of patients diagnosed with JIA or with a non-inflammatory joint pain (NJP) were selected. Standard statistical techniques were used for evaluation. In total, 165 of 800 questionnaires could be used for evaluation. Of the 800 patients who completed questionnaires, 133 were diagnosed with JIA and 32 with NJP. The analysis of the individual questions was performed by comparing the rate of a positive response to the questions between the two groups. Four questions showed a significant difference by comparing the groups, using JIA patients with at least one active joint. The diagnostic accuracy of the weighted sum score increased from 64 to 68% to discriminate between the groups in comparison to the ordinary sum score. An optimal cutoff of 6.0 for referral to a pediatric rheumatologist was calculated. The validation of the SICJIA showed a discriminative difference in patients with clinical diagnosed JIA and a control group diagnosed with NJP. The weighted sum score performed better to differentiate between JIA and NJP patients. The modified SICJIA can be useful to identify patients at risk of JIA.