Validity of the King's Health Questionnaire in the assessment of quality of life in patients with urinary incontinence

BACKGROUND: TO assess the validity of the Spanish version of the King's Health Questionnaire (KHQ) for measuring the quality of life of women with different types of urinary incontinence. PATIENTS AND METHODS: 77 women with urinary stress incontinence (USI), 51 with urge incontinence (UUI) and 34 with mixed urinary incontinence (MUI) were consecutively recruited. Subjects were diagnosed using urodynamic tests. Patients completed the KHQ and SF-36 questionnaires on inclusion in the study, after 15 days, and again after one month. RESULTS: There were no significant differences in socio-demographic and QOL characteristics between different UI groups. UUI and MUI patients had greater urinary frequency and urge than USI patients, and USI and MUI patients had a greater number of leakage episodes than UUI patients. Correlations between dimensions on the KHQ and the SF-36 were moderate to strong. Women with greater urinary frequency, greater urgency, more incontinence episodes during the week and who used pads and nappies perceived a worse quality of life. Changes in these variables correlated with changes in HRQOL. The internal consistency of dimensions was good (0.65-0.92) as was test-retest reliability (0.68-0.88). Dimensions most sensitive to change after one month of treatment were impact of UI, seriousness of UI, and the symptoms scale (effect size greater than 0.6). CONCLUSION: The KHQ is a valid instrument for measuring the quality of life of patients with different types of UI. Improvements in urinary frequency, urinary urgency, number of leakage episodes, and changes in the type of protective material produces an increase in HRQOL.