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. The ENDOPAIN-4D enables multidimensional assessment of pain in women with endometriosis.The Portuguese version was translated, culturally adapted, and validated.The instrument showed excellent internal consistency and preserved factor structure.Further studies are needed to confirm concurrent validity and stability.This validation supports more patient-centered, evidence-based care in Portugal. The ENDOPAIN-4D enables multidimensional assessment of pain in women with endometriosis. The Portuguese version was translated, culturally adapted, and validated. The instrument showed excellent internal consistency and preserved factor structure. Further studies are needed to confirm concurrent validity and stability. This validation supports more patient-centered, evidence-based care in Portugal.