Validation of a single summary score for the Prolapse/Incontinence Sexual Questionnaire-IUGA revised (PISQ-IR)

Abstract

Introduction and hypothesis: The Prolapse/Incontinence Sexual Questionnaire-International Urogynecology Association (IUGA) Revised (PISQ-IR) measures sexual function in women with pelvic floor disorders (PFDs) yet is unwieldy, with six individual subscale scores for sexually active women and four for women who are not. We hypothesized that a valid and responsive summary score could be created for the PISQ-IR.

Methods: Item response data from participating women who completed a revised version of the PISQ-IR at three clinical sites were used to generate item weights using a magnitude estimation (ME) and Q-sort (Q) approaches. Item weights were applied to data from the original PISQ-IR validation to generate summary scores. Correlation and factor analysis methods were used to evaluate validity and responsiveness of summary scores.

Results: Weighted and nonweighted summary scores for the sexually active PISQ-IR demonstrated good criterion validity with condition-specific measures: Incontinence Severity Index = 0.12, 0.11, 0.11; Pelvic Floor Distress Inventory-20 = 0.39, 0.39, 0.12; Epidemiology of Prolapse and Incontinence Questionnaire-Q35 = 0.26 0,.25, 0.40); Female Sexual Functioning Index subscale total score = 0.72, 0.75, 0.72 for nonweighted, ME, and Q summary scores, respectively. Responsiveness evaluation showed weighted and nonweighted summary scores detected moderate effect sizes (Cohen's d > 0.5). Weighted items for those NSA demonstrated significant floor effects and did not meet criterion validity.

Conclusions: A PISQ-IR summary score for use with sexually active women, nonweighted or calculated with ME or Q item weights, is a valid and reliable measure for clinical use. The summary scores provide value for assesing clinical treatment of pelvic floor disorders.

Keywords: PISQ-IR; Pelvic floor disorders; Prolapse; Sexual function; Validated questionnaire.