Psychometric evaluation of 2 comprehensive condition-specific quality of life instruments for women with pelvic floor disorders

Abstract

Objective: To evaluate the psychometric properties of the Pelvic Floor Distress Inventory (PFDI) and the Pelvic Floor Impact Questionnaire (PFIQ). Methods: The PFDI and PFIQ are based on the structure and content of two previously validated questionnaires (the Urinary Distress Inventory [UDI] and the Incontinence Impact Questionnaire [IIQ]) and have additional questions regarding pelvic organ prolapse and colorectal dysfunction. The PFDI assesses symptom distress in women with pelvic floor disorders and has 3 scales: UDI (28 items), Colorectal–anal Distress Inventory (17 items), and Pelvic Organ Prolapse Distress Inventory (16 items). The PFIQ assesses life impact and also has 3 scales: IIQ, Colorectal–anal Impact Questionnaire, and the Pelvic Organ Prolapse Impact Questionnaire (31 items each). One hundred women with pelvic floor symptoms were enrolled and completed both the PFDI and PFIQ at baseline and again 1 week later. Patients underwent a comprehensive evaluation that included a structured history, Pelvic Organ Prolapse Quantitation, and a 1-week prospective bowel/bladder diary. Patients with urinary incontinence and stage III or IV pelvic organ prolapse also had a urodynamic evaluation. Results: Each scale of the PFDI and PFIQ proved to be internally consistent (αs: PFDI.82-.89; PFIQ.96-.97) and reproducible (interclass correlations: PFDI.86-.87; PFIQ.77-.92). Both the UDI and the IIQ significantly correlated with the number of urinary incontinence episodes per week (ρ =.26, P <.05; ρ =.46, P <.0001, respectively) and the number of pads used per week (ρ =.26, P <.05; ρ =.40, P <.0001, respectively). The Pelvic Organ Prolapse Distress Inventory and the Pelvic Organ Prolapse Impact Questionnaire significantly correlated with the stage of prolapse (ρ =.32 and ρ =.33, P <.01 each), and the Colorectal–anal Distress Inventory and Colorectal–anal Impact Questionnaire significantly correlated with the number of fecal incontinence episodes per month (ρ =.49, P <.0001 and ρ =.30, P <.01) and a diagnosis of defecatory dysfunction (ρ =.47, P <.0001 and ρ =.29, P <.01). The total time taken to complete both instruments averaged 23 minutes (range, 9-55). Conclusion: The PFDI and the PFIQ are reliable, valid, condition-specific quality of life instruments for women with pelvic floor disorders. (Am J Obstet Gynecol 2001;185:1388-95.)