Psychometric evaluation of health-related quality-of-life measures after pelvic organ prolapse surgery.

OBJECTIVE: To evaluate the psychometric characteristics of the Pelvic Floor Distress Inventory (PFDI-20), the Pelvic Floor Impact Questionnaire (PFIQ-7), and the Patient Global Impression of Change (PGIC) among women undergoing pelvic organ prolapse (POP) repair surgery.

METHODS: Data were collected at baseline and 12 months from 2 single-arm trials of surgical repair of POP using mesh. At each time point, internal consistency reliability (Cronbach's α) was calculated for the PFDI-20 and PFIQ-7 total scores and for each subscale. Concurrent validity was assessed with baseline and follow-up data using Spearman's rank-order correlation coefficients. Responsiveness was assessed by calculating change scores from baseline to each follow-up visit, effect sizes, standard error of measurement (SEM), and using PFDI-20 and PFIQ-7 change scores stratified by PGIC.

RESULTS: The women (N=275: study 1, n=148; study 2, n=127) had a mean (SD) of 64.4 (10.3) years of age. At baseline, the women had a mean (SD) stage II (n=83), stage III (n=173), or stage IV (n=19) POP quantification. At baseline, the internal consistency reliability of the PFDI-20 full and subscales ranged from 0.64 to 0.85, and that of the PFIQ-7 ranged from 0.89 to 0.96. Concurrent validity was good for the PFDI-20 and PFIQ-7 (r range, 0.35-0.59). The PFDI-20, the PFIQ-7, and the PGIC were responsive.

CONCLUSION: The PFDI-20, the PFIQ-7, and the PGIC are psychometrically sound measures of patients' perceptions of change after POP surgery and will be useful for those interested in evaluating perceptions of patients undergoing surgical POP repair.