Pelvic Floor Distress Inventory (PFDI - 20)
Original Editor - Kirsten Ryan
The PFDI-20 is both a symptom inventory and a measure of the degree of bother and distress (quality-of-life) caused by pelvic floor symptoms. It is a short-form version of the Pelvic Floor Distress Inventory.
Method of Use
The PFDI-20 includes 20 questions and 3 scales. Each of the 3 scales is scored from 0 (least distress) to 100 (greatest distress). The sum of the scores of these 3 scales serves as the overall summary score of the PFDI-20 and ranges from 0 - 300. The 3 scales include questions taken from the following widely used outcome measures: Urinary Distress Inventory - 6 questions, Pelvic Organ Prolapse Distress Inventory - 6 questions, and Colorectal-Anal Distress Inventory - 8 questions.
The PFDI-20 has good test-retest reliability intraclass coefficient .86, P< .001. Each of the 3 scales (Urinary Distress Inventory, Pelvic Organ Prolapse Distress Inventory, and Colorectal-Anal Distress Inventory) demonstrates significant correlation with their long-form scales (r = .86, r = .92, and r = .93, respectively, P < .0001.
The PFDI-20 demonstrates construct validity as it demonstrates a significant association with appropriate measures of symptom severity and pelvic floor diagnoses.
Each of the 3 scales of the PFDI-20 demonstrated moderate to excellent responsiveness with effect size and standardized response mean values ranging from .70 to 1.28. The sensitivity of the PFDI-20 as a whole was excellent with an effect size of 1.48 P < .0001 and standardized response mean of 1.09 P < .0001. The ability of the PFDI-20 to discriminate between subjects who indicated that they were "worse" after surgery from those who indicated they were "better" was excellent with c-statistic of .95.
The strength of the PFDI-20 is that it is a short form that gives a comprehensive assessment of the effect of pelvic floor disorders on the quality of life of women, rather than assessing just one aspect of pelvic floor function such as urinary incontinence. A more generic quality-of-life form as the SF-36 has demonstrated poor responsiveness in patients undergoing treatment for urinary incontinence. In these patient populations, it may be important to use both a generic quality-of-life instrument and a condition-specific instrument that has demonstrated responsiveness. The PFDI-20 is easy to use in both clinical and research settings.
- Overview of PFDI-20 on the Rehabilitation Measures Database.
- Link to the PFDI-20 on Beaumont Women's Health Center Website.
- Paper by Barber et al 2005 describing the development of the PFIQ-7
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- Barber MD, Walters MD, Bump RC. Short forms of two condition-specific quality-of-life questionnaires for women with pelvic floor disorders (PFDI-20 adn PFIQ-7). Am J Obstet Gynecol 2005;193:103-113.
- Crosby RD, Kolotkin RL, Rhys Willisams G. Deﬁning clinicallyfckLRmeaningful change in health-related quality of life. J ClinfckLREpidemiol 2003;56:395-407