Sex Differences in Experiencing and Reporting Low Back Pain Using Standardised Questionnaires: A Cross-Sectional Study.

Chronic low back pain (CLBP) is one of the leading causes of disability. Evidence suggests that women experience and report pain differently than men, showing lower thresholds, greater intensity, and higher frequency of pain reports. Understanding these differences is crucial for the interpretation of standardized questionnaires. The aim of the study was to investigate sex differences in the descriptors of the McGill Pain Questionnaire (MPQ) chosen by men and women with CLBP and their relationship with pain intensity. This is a descriptive, cross-sectional, and observational study. Men and women with nonspecific CLBP aged 18-80 years and numerical pain rating scale (NPRS) > 1, were recruited. Participants completed sociodemographic forms, NPRS and the MPQ. The study assessed 310 participants (women: n = 201, 64.8%; men: n = 109, 35.2%). Out of the 20 subcategories analysed, five showed a difference in the prevalence of words between sexes (subcategories 1, 5, 6, 9, and 11). The most frequently selected words of the MPQ, with over 80% of responses, were 'crushing', 'aching', 'tiring', 'tight', and 'cool'. A correlation was found between NPRS and total PRI, sensory PRI, and miscellaneous PRI were observed only in women (p < 0.05, r > 0.3). This study reinforces the importance of considering sex when interpreting standardized questionnaires in CLBP. Although pain intensity measured by the NPRS did not differ significantly between sexes, women presented higher MPQ-derived scores and different qualitative pain descriptors. These findings suggest that qualitative pain expression may differ between sexes and should be interpreted within a broader biopsychosocial context.