Psychometric evaluation and cross-cultural adaptation of the Australian Pelvic Floor Questionnaire (APFQ-IR) in Iranian reproductive age women

Abstract

Pelvic floor disorders (PFDs), as a silent alert, is one of the pervasive debilitating health concerns among women all over the world, such that in developed countries, one in four women, suffers from PFDs. Validity and reliability of the Australian Pelvic Floor Questionnaire (APFQ) has not been determined in Iran, so to determine APFQ’s psychometric characteristics, we decided to conduct this study on women of reproductive age in Tabriz city, Iran. This methodological cross-sectional study was intended to determine the psychometric properties of the Persian version of the APFQ-IR in 5 steps including “translation process, content validity, face validity, construct validity (exploratory and confirmatory factor analyses and examination of ceiling and floor effects) and reliability” on 400 reproductive age women referring to health centers in Tabriz city, Iran, with cluster random sampling method in the period between May 2022 to September 2022. The translation process was done based on two approaches, Dual panel, and Beaton et al.’s five steps. Then, in order to evaluate content validity, face validity, and construct validity, 10 instrument and PFDs experts, 10 women from the target group investigated the instrument's items, and 400 eligible women completed the instrument. Finally, to determine the reliability, two internal consistency methods, (Cronbach's alpha and McDonald's omega) and test–retest method (ICC) were used. In the present study, content validity assessment of APFQ-IR, showed a good level of validity (CVR = 0.96, CVI = 0.94). To assess construct validity, exploratory factor analysis results on 36 items, led to the identification of 4 factors including bladder function, bowel function, prolapse symptom and sexual function, which explained 45.53% of the cumulative variance and indicated the sufficiency of the sample size (Kaiser–Meyer–Olkin = 0.750). Implementing confirmatory factor analysis, (RMSEA = 0.08, SRMR = 0.08, TLI = 0.90, CFI = 0.93, χ2/df = 3.52) confirmed the model fit indices. Finally the internal consistency and reliability was high for the entire instrument (Cronbach’s alpha = 0.85; McDonald's omega (95% CI) = 0.85 (0.83–0.87) and Intraclass Correlation Coefficient (95% CI) = 0.88 (0.74–0.94)). The Persian version of the APFQ-IR, has a good validity and reliability and has acceptable psychometric properties, thus can be used both for research purposes and for clinical evaluation of pelvic floor disorders symptoms in health centers.