Responsiveness of the Pelvic Floor Distress Inventory and Pelvic Floor Impact Questionnaire in women undergoing treatment for pelvic floor disorders.

INTRODUCTION AND HYPOTHESIS: This study evaluated the responsiveness and minimal important differences (MID) of the Chinese Pelvic Floor Distress Inventory (PFDI) and Pelvic Floor Impact Questionnaire (PFIQ) in women undergoing urodynamic stress incontinence (USI) and/or pelvic organ prolapse (POP) treatment.

METHODS: One hundred and fifty-six women were assessed using the PFDI and PFIQ before and after they received continence surgery and or pelvic floor repair (PFR) surgery, or vaginal pessary. Symptom severity was recorded using a visual analog scale (VAS) before and after treatment as was rating of their satisfaction with the treatment they received. Responsiveness of the PFDI and PFIQ were evaluated by effect sizes, standardized response mean, paired samples t test or Wilcoxon Signed Rank Test. MID in the PFDI and PFIQ for different treatments were determined by satisfaction rating, change in VAS scoring, and distribution-based methods.

RESULTS: There were significant improvements in the respective subscales of PFDI and PFIQ, demonstrating moderate to great responsiveness after different treatments. The estimation of MID for the Urinary Distress Inventory (UDI) was -30 to -14 and the Urinary Impact Questionnaire (UIQ) was -28 to -14 for women who underwent continence surgery. The MID for the Pelvic Organ Prolapse Distress Inventory (POPDI) was -44 to -21, the Pelvic Organ Prolapse Impact Questionnaire (POPIQ) -40 to -27, the UDI -22 to -16, the UIQ -37 to -31, the Colo-Rectal-Anal Distress Inventory (CRADI) -37 to -14, and the Colo-Rectal-Anal Impact Questionnaire (CRAIQ) -34 to -6 for women who underwent PFR surgery; and estimation of MID for the POPDI was -16, the POPIQ -29, the UDI -28, the UIQ -17, the CRADI -25, and the CRAIQ -31 for women who received a vaginal pessary. The MID of the respective subscales were supported by the distribution-based methods.

CONCLUSIONS: The Chinese PFDI and PFIQ instruments are responsive to change in women undergoing continence surgery, PFR surgery or vaginal pessary for USI or POP.