Children's Somatization Inventory: psychometric properties of the revised form (CSI-24)

To conduct a multimethod psychometric evaluation to refine the Children's Somatization Inventory (CSI) and to investigate its dimensionality.

The CSI was administered to 876 pediatric patients with chronic abdominal pain at their initial visit to a pediatric gastroenterology clinic. Tools from three psychometric models identified items that most effectively measured the construct of somatization and examined its dimensionality.

Eleven statistically weak items were identified and removed, creating a 24-item CSI (CSI-24). The CSI-24 showed good psychometrics according to the three measurement models and correlated .99 with the original CSI. The CSI-24 has one dominant general factor but is not strictly unidimensional.

The CSI-24 is a reliable and psychometrically sound refinement of the original CSI. Findings are consistent with the view that somatization has a strong general factor that represents a continuum of symptom reporting, as well as minor components that represent specific symptom clusters in youth with chronic abdominal pain.