Psychological Pain Measurement in the Context of Suicidal Behavior: Rasch Analysis of the Spanish Psychache Scale...

Background: The Psychache Scale (PS) is the most widely used scale to measure psychological pain due to its ease of application, favorable evidence of predictive validity, and adequate psychometric properties from the CTT (Classical Test Theory) approach. This paper aims to contribute to the improvement of the Spanish version of the PS by analyzing its psychometric properties using a Rasch model. Methods: Using quota sampling, 905 young adults completed an online questionnaire with the PS. Results: The items and response categories showed an acceptable fit to the model and good performance. The separation index indicated three strata for persons. The item-person map showed that persons were placed lower on the psychological pain continuum than item, and some item pairs presented small difference in their severity. The study of men-women DIF (differential item functioning) showed a slight differential functioning only for item 6. Conclusions: This study provides new evidence that supports the use of the PS to measure psychological pain.