ICIQ symptom and quality of life instruments measure clinically relevant improvements in women with stress urinary incontinence
To determine whether changes in questionnaire scores on symptoms and condition-specific quality of life reflect clinically relevant improvements in women with stress urinary incontinence (SUI).We retrospectively analyzed questionnaires collected during a randomized controlled trial in women with SUI, that received pelvic floor muscle training (PFMT) in two different formats. We included 218 women that answered validated self-assessment questionnaires at baseline and at a 4-month follow-up. We registered changes on two questionnaires, the International Consultation on Incontinence Modular Questionnaire-Urinary Incontinence Short Form (ICIQ-UI SF) and the Lower Urinary Tract Symptoms Quality of Life (ICIQ-LUTSqol). We compared these score changes to responses from the Patient Global Impression of Improvement (PGI-I) questionnaire. Differences were analyzed with the Spearman rho and one-way-ANOVA. The minimum important difference (MID) was the mean change in score for women that experienced a small improvement.The PGI-I correlated significantly to both the ICIQ-UI SF (r = 0.547, P < 0.0001) and ICIQ-LUTSqol (r = 0.520, P < 0.0001). Thus, larger reductions in symptoms or quality of life scores were associated with greater impressions of improvement. The changes in ICIQ-UI SF and ICIQ-LUTSqol scores were significant across all PGI-I groups from "no change" to "very much improved" (P < 0.05). The MIDs were 2.52 (SD 2.56) for ICIQ-UI SF and 3.71 (SD 4.95) for ICIQ-LUTSqol.The change in ICIQ-UI SF and ICIQ-LUTSqol scores after PFMT reflected clinically relevant improvements in women with SUI. The MIDs established for this population may facilitate future research, treatment evaluations, and comparisons between studies.