Psychometric properties of the Swedish version of the Functional Disability Inventory

Abstract

Chronic or recurrent pain is a common experience in children and adolescents. One questionnaire that is frequently used to assess pain-related disability is the Functional Disability Inventory (FDI). The aim of this study was to evaluate the psychometric properties of the Swedish version of the FDI. The patient group consisted of 30 patients, 8–17 years old. The comparison group consisted of 78 pupils, 8–17 years old. Reliability was assessed using Cronbach's alpha and intraclass correlation (ICC). Validity was assessed in terms of construct validity and face validity. To assess construct validity, Spearman's rho was used. Internal consistency reliability was high, with Cronbach's α = 0.90. Similarly, test–retest reliability was good, with an ICC of 0.90 (95% confidence interval 0.78–0.95). Concerning interrater reliability, the result was good, with an ICC of 0.67. Construct validity correlations, assessed using Spearman's rho, were significant. Most participants (85.7%) did not report any areas in their everyday lives where they experienced any disabilities not covered in the FDI, indicating acceptable face validity. In this context and used in this population, the results indicate that the FDI is a reliable and valid questionnaire for assessing pain-related disability in children and adolescents.

Key words::

• Adolescents
• biopsychosocial
• children
• pain
• questionnaire

Acknowledgements

We would like to thank Jacquelyn Collins and Karin Fischer-Buder for their help with the English language.

Funding

Å. B. Tornberg received funding from the World Village of Women's Sports Foundation.

Declaration of interest: The authors declare that they have no financial or other relationships that might lead to a conflict of interest.

Author contributions: Both authors contributed to the design of the study and to the manuscript by discussion, critical comments and analysis of data. Both authors approved the manuscript.