Concurrent validity, internal consistency and responsiveness of the Portuguese version of the King's Health Questionnaire (KHQ) in women after stress urinary incontinence surgery.

OBJECTIVE To evaluate the concurrent validity, internal consistency and responsiveness of King's Health Questionnaire (KHQ) in patients who underwent sling procedures for the treatment of stress urinary incontinence. MATERIALS AND METHODS We performed a prospective open label multicenter study in 4 tertiary referral centers. Sixty-eight female patients were enrolled with urodynamically diagnosed urinary stress incontinence. Patients were treated using surgical procedures, mostly (73%) with the synthetic sling procedure, which has been considered one of the gold standard methods for the treatment of urinary incontinence. The patients were assessed before and after one month of postoperative follow up, using the KHQ in its validated Portuguese version. Patients also underwent preoperative urodynamic test, Stamey incontinence grading, pad usage and the assessment of number of pads used per day. After surgery, patients underwent stress test, Stamey incontinence grading pad usage and the assessment of number of pads used per day. RESULTS The concurrent validity showed good correlations in some domains of KHQ to clinical parameters. The internal consistency was higher after treatment compared to preoperative values. Objective parameters, such as pad usage and the assessment of number of pads used per day, had significant correlation with changes in post-treatment scores on KHQ. The responsiveness expressed in terms of standardized effect size (SES) and standardized response mean (SRM) was large. CONCLUSION The results showed moderate concurrent validity, strong internal consistency and high responsiveness for KHQ, indicating that it is suitable for measuring outcomes in clinical trials among female patients with stress urinary incontinence.