Patient perceptions of foot disability in Juvenile Idiopathic Arthritis: a comparison of the juvenile arthritis foot disability index and the Oxford ankle foot questionnaire for children

BACKGROUND: The Juvenile Arthritis Foot Disability Index (JAFI) and the Oxford Ankle Foot Questionnaire for Children (OxAFQ-C) are two region-specific paediatric outcome tools that measure the impact on well-being in children with foot pathology. The aim of this study was to establish the level of agreement between the JAFI and the OxAFQ-C in a group of children diagnosed with Juvenile Idiopathic Arthritis (JIA). METHODS: Children with JIA accessed the questionnaire via a website. The OxAFQ-C questionnaire and the JAFI questionnaire were combined into one document consisting of 42 statements with Likert-scale responses. A further question regarding duration of disease was added. On completion, the web-linked questionnaire was returned by e-mail. RESULTS: Thirty five participants were included. Individual domain and composite score analysis was undertaken. The JAFI participation domain was compared to the OxAFQ-C school domain and showed no significant difference between the median scores of each participant (z = -1.33, p = 0.181). The JAFI activity and the OxAFQ-C physical domains were compared and showed that a significant difference between the median scores existed (z = -4.29, p < 0.001). Agreement between the two PROMs was tested using Bland Altman Levels of Agreement based upon the percentage summed composite scores. Levels of agreement between the scores were considered to be poor based on the Bland Altman plot, despite a low mean difference in scores (mean difference = -3.88, SD of difference = 9.93, p = 0.027). Pearson correlation was undertaken to measure the relationship between the summed composite score and disease duration. No relationship was found (JAFI: r = -0.08, p = 0.672; OxAFQ-C: r = 0.037, p = 0.871). CONCLUSIONS: This study has shown that despite some agreement between the individual domains, overall there is poor agreement between the OxAFQ-C and the JAFI percentage summed composite scores. The study is not able to determine if one score is superior to the other but both scores could be of value when used in this population.