Psychometric properties of the Functional Disability Inventory for assessing Pain-related disability in children from the community.

PURPOSE: The aim of this study was to evaluate the psychometric properties of the Functional Disability Inventory for assessing pain-related disability in a community sample of children and adolescents.

MATERIALS AND METHODS: Five hundred and sixty-one schoolchildren (aged 8-18 years) completed the Functional Disability Inventory. They were also administered measures assessing anxiety sensitivity, internalizing pain coping behaviors, social support seeking, and positive self-statements. A subset of 107 participants completed measures of quality of life.

RESULTS: The results confirmed the two-factor structure solution for the Functional Disability Inventory items. The measure's scales scores demonstrated adequate to good internal consistencies. Convergent validity was supported by significant positive correlations between FDI scores and anxiety sensitivity and internalizing pain coping behaviors, and negative correlations with quality of life. Discriminant validity was supported by weak and non-significant correlations between disability scores and the social support seeking and positive self-statements pain coping strategies scores. Differences in the disability scores between participants who did not experience pain in the last 3 months and those that experienced at least some pain provided additional evidence for construct validity.

CONCLUSIONS: The findings support the Functional Disability Inventory as a reliable and valid measure for assessing pain-related disability in children and adolescents from the community. Implications for rehabilitation Chronic pain is a common health problem in youths and is associated with disability (which implies difficulties in physical, psychological, social or school functioning). The FDI is one of the most used measures to assess disability in youths with chronic pain. However, its psychometric properties have not been studied in a community sample. This study shows new and important findings demonstrating that the FDI provides reliable and valid scores when used to assess pain-related disability in a community sample of schoolchildren. These findings support the use of the FDI as a measure of the benefits of community-based pain treatments or the benefits of disability prevention programs over time.