WHODAS measurement properties for women with dysmenorrhea

BACKGROUND: There is an association of dysmenorrhea with human functioning and disability. However, no patient-reported outcome measure has been developed to assess this construct in women with dysmenorrhea. WHODAS 2.0 has been recognized as an important generic patient-reported outcome information of physical function and disability. Thus, the aim of this study was to assess the measurement properties of the WHODAS 2.0 in women with dysmenorrhea. METHODS: This is an online and cross-sectional study conducted with Brazilian women aged 14 to 42 years with self-report of dysmenorrhea in the last three months. According to COSMIN, structural validity was evaluated by exploratory and confirmatory factor analysis; internal consistency by Cronbach’s Alpha; measurement invariance by multigroup confirmatory factor analysis between geographic regions of Brazil; and construct validity by correlating WHODAS 2.0 to the Numerical Rating Scale for pain severity. RESULTS: One thousand three hundred and eighty-seven women (24.7 ± 6.5 years) with dysmenorrhea participated in the study. WHODAS 2.0 presented a single factor by exploratory factor analysis and adequate model by confirmatory factor analysis (CFI = 0.924, TLI = 0.900, RMSEA = 0.038), excellent internal consistence (α = 0.892) for all items and an invariancy across geographic regions (ΔCFI ≤ 0.01 and ΔRMSEA < 0.015). Correlation between WHODAS 2.0 and numerical rating scale was positive and moderate (r = 0.337). CONCLUSION: WHODAS 2.0 has a valid structure to assess functioning and disability related to dysmenorrhea in women.