Psychometric properties of the Brief Symptom Inventory-18 in a Spanish breast cancer sample

ObjectiveThe objective of this work was to study the psychometric and structural properties of the Brief Symptom Inventory-18 (BSI-18) in a sample of breast cancer patients (N=175).MethodsConfirmatory factor analyses were conducted. Two models were tested: the theoretical model with the original structure (three-dimensional), and the empirical model (a four-factor structure) obtained through exploratory factor analysis initially performed by the authors of the BSI-18.ResultsThe eligible structure was the original proposal consisting of three dimensions: somatization, depression, and anxiety scores. These measures also showed good internal consistency.ConclusionThe results of this study support the reliability and structural validity of the BSI-18 as a standardized instrument for screening purposes in breast cancer patients, with the added benefits of simplicity and ease of application.