The experience of chronic non-cancer pain differs between women and men due to gender-related factors. This study (1) assessed the difference in responses to the impact of chronic non-cancer pain on daily life in women and men using the PAIN_Integral Scale© and (2) evaluated its invariance through multigroup confirmatory factor analysis. This was conducted by means of an analysis of invariance through a multigroup confirmatory factor analysis. A cross-sectional sample of 400 participants over 18 years of age with Chronic Non-Oncological Pain in Pain Units and Primary Care Centres belonging to the Spanish Public Health System was recruited (January to March 2020). An analysis was performed to assess whether any of the items in the instrument showed different behaviours. All analyses were performed using AMOS® v.26 software. The results showed that the structure of the PAIN_Integral© Scale remained adequate when analysing its invariance in women and men, showing no metric, scalar and/or strict invariance. Therefore, these results indicated that the PAIN_Integral Scale© instrument has a different interpretation for women and men, identifying eight items with a singular functioning in both sexes and belonging to the subscales of proactivity, resilience and support network. These findings can be explained by gender stereotypes, since the dimensions where there are differences have an important social burden.
Keywords: chronic pain; factor analysis; female; male; statistical; surveys and questionnaires; validation.