Translation and measurement properties of the pelvic floor distress inventory-short form (PFDI-20) in Iranian reproductive age women

BACKGROUND: Every year, millions of women worldwide suffer in silence from pelvic floor disorders (PFDs) as an annoying health problem. Despite the high prevalence rate and negative effects of PFDs on the quality of life, the validity and reliability of pelvic floor distress inventory-short form (PFDI-20) has not been confirmed for Iranian women of reproductive age. Hence, this study aimed to determine measurement properties of PFDI-20 among women of reproductive age in Tabriz, Iran. METHODS: The current study was cross-sectional research that selected 400 women of reproductive age referring to health centers in Tabriz City, by using cluster random sampling from May 2022 to September 2022. Measurement properties of the Persian version of PFDI-20 were determined and evaluated through five steps, including content and face validity within two quantitative and qualitative parts, structural validity by using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA), and reliability testing through internal consistency, test-retest reliability, and measurement error. Moreover, ceiling and floor effects were investigated. RESULTS: In this research, CVI (content validity index) and CVR (content validity ratio) of PFDI-20 equaled 0.94 and 0.97, respectively. In addition, the EFA process was applied to 20 items and derived the structure of three factors, which explained 58.15% of the total variance. In CFA phase, values of fit indicators (RMSEA = 0.07, SRMR = 0.07, TLI = 0.97, CFI = 0.99, x2/df = 3.19) confirmed the model validity. To determine reliability, Cronbach’s alpha = 0.84; McDonald’s omega (95% CI) = 0.84 (0.82 to 0.87) and Intraclass Correlation Coefficient (95% CI) = 0.98 (0.97 to 0.99) were obtained. Also, the SEM was 2.64, and the SDC indicating the smallest individual change was 8.91. Regarding the inventory feasibility, the ceiling effect was not observed in total value and subscales, while the floor effect in the total score of PFDI-20 equaled 24.0. The latter rate equaled 45.8, 38.3, and 50.8 for subscales POPDI-6, CRADI-8, and UDI-6, respectively. CONCLUSIONS: Persian version of PFDI-20 is a valid and reliable scale used to evaluate PFDs in Iranian women of reproductive age. Healthcare professionals can use this scale to screen PFDs, and researchers can consider it a reliable tool for their studies.