Empirical classification of children with JIA: a multidimensional approach to pain and well-being

To investigate the relationship between children's arthritis self-efficacy, trait-anxiety, depression, clinical state of the disease (pain, disability, number of somatic complaints and active joints) and age of the child.

Trait anxiety and depression of JIA patients were measured by standardized scales (STAIC and CDI). For assessing self-efficacy CASE-scale was used. Pain, CHAQ and active joint count were used as indicators of the disease severity. The K-means cluster procedure was used to classify 145 consecutively recruited patients aged 8 to 15, regarding age, trait-anxiety and depression. One-way multivariate analysis of variance (MANOVA) followed by separate ANOVA's was used for comparisons between the cluster groups. Associations between the cluster groups and the children's self-efficacy were then evaluated using multivariate analysis of variance (MANOVA).

Four cluster groups were identified based on the degree of depression and trait-anxiety. Clinical disease-related parameters differed significantly in the cluster groups. Pain was not necessarily related to the severity of the disease or to the diagnosis (oligoarthritis, oligoextended and polyarthritis). A higher level of self-efficacy was related to lower levels of depression, trait anxiety and pain.

In JIA, the clinical classification of disease activity and severity did not directly correspond with depression and trait-anxiety in children with JIA. Instead, these were regulated by a self-efficacy, which was associated with less pain and somatic complaints.