ORIGINAL ARTICLE Reliability and validity of the Japanese version of the pelvic floor distress inventory-short form 20 Mikako Yoshida & Ryoko Murayama & Erika Ota & Maki Nakata & Shiro Kozuma & Yukio Homma Received: 9 May 2012 / Accepted: 27 September 2012 / Published online: 19 October 2012 # The International Urogynecological Association 2012 Abstract Introduction and hypothesis The aim of this study was to translate the Pelvic Floor Distress Inventory-Short Form 20 (PFDI-20) into Japanese and test its reliability and validity among Japanese women. Methods Fifty-nine women with and without pelvic floor disorders (age 55.8±16.8 years, mean ± SD) completed the Japanese PFDI-20 (J-PFDI-20) questionnaire at baseline and 2 weeks later. Intraclass correlation coefficients (ICC) and the Bland and Altman method for test-retest reliability and Cronbach’ s alpha for internal consistency of the J-PFDI-20 were used. Scores of total and subscales were compared between women with and without pelvic floor disorders for known-groups validity. Spearman’ s correlation coeffi- cients between the J-PFDI-20 and the severity of pelvic floor disorders and Urinary Incontinence Quality of Life Scale (I-QOL) were used for construct validity. Results The PFDI-20 was successfully translated from En- glish into Japanese with face validity through rigorous cross- cultural validation. Test-retest reliability of the J-PFDI-20 and three subscales was good to excellent (ICC 0 0.77–0.90). The Bland and Altman analysis showed that differences between the first and second scores of total J-PFDI-20 and its subscales were not significantly different from 0 and largely fell within the range of 0±1.96 SD. Cronbach’ s alpha values were 0.52–0.83. Analysis of known-groups validity showed differ- ences in scores of the J-PFDI-20 between women with and without pelvic floor disorders. Acceptable construct validity was found in J-PFDI-20 total and subscale scores with posi- tive correlations to severity of pelvic floor disorders (ρ >0.35) and negative correlations to I-QOL (ρ <-0.39). Conclusions The results suggest that the J-PFDI-20 is a reliable and valid condition-specific quality of life instru- ment for women with pelvic floor disorders. Keywords Fecal incontinence . Pelvic floor . Pelvic organ prolapse . Quality of life . Urinary incontinence Introduction Pelvic floor disorders, such as urinary incontinence, fecal incontinence, and pelvic organ prolapse, are associated with poor quality of life (QOL) in women [1, 2]. Assessment of condition-specific QOL related to pelvic floor disorders is essential both for making a diagnosis and evaluating the efficacy of a particular treatment in the clinical setting. In M. Yoshida (*) Department of Gerontological Nursing/Wound Care Management, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan e-mail: mokka-tky@umin.ac.jp R. Murayama Department of Nursing, The University of Tokyo Hospital, Tokyo, Japan E. Ota Department of Global Health Policy, The University of Tokyo, Tokyo, Japan M. Nakata Department of OB/GYN, Mitsui Memorial Hospital, Tokyo, Japan S. Kozuma Department of OB/GYN, The University of Tokyo, Tokyo, Japan Y. Homma Department of Urology, The University of Tokyo, Tokyo, Japan Int Urogynecol J (2013) 24:1039–1046 DOI 10.1007/s00192-012-1962-1