Translation, cultural adaptation, and validation of the Portuguese version of ENDOPAIN-4D questionnaire

The endometriosis painful symptoms-4 dimensions ENDOPAIN-4D is a multidimensional questionnaire designed to assess endometriosis-related pain. This study aimed to translate, culturally adapt, and validate ENDOPAIN-4D for European Portuguese.

Translation and content validity assessment were assessed in 32 women with endometriosis. For psychometric validation, 386 patients completed an online sociodemographic and clinical questionnaire, the Portuguese ENDOPAIN-4D, and the Endometriosis Health Profile Questionnaire-30 (EHP-30). Statistical analyses included descriptive statistics, exploratory factor analysis, internal consistency, item-total correlation, and concurrent validity.

Factor analysis of the "usual pain" dimension supported the original four-factor structure, accounting for 63.7% of variance (Cronbach's α = 0.91). A novel three-factor structure was identified for the "worst pain" dimension, previously psychometrically untested, with good internal consistency (Cronbach's α = 0.83) and acceptable item-total correlations. Concurrent validity with the EHP-30 ranged from weak to strong across domains.

The Portuguese ENDOPAIN-4D is a culturally adapted and validated instrument for multidimensional pain assessment in European Portuguese women with endometriosis, with validity likely limited for other Portuguese-speaking communities. The newly identified three-factor structure for worst pain may aid individualized pain management and follow-up in clinical and psychosomatic care. Further studies should evaluate concurrent validity and the stability and responsiveness of the new algorithms.