Validity of utility measures for women with urge, stress, and mixed urinary incontinence

Abstract

Objective: We sought to evaluate the construct validity of 3 health status classification system instruments-Health Utilities Index Mark 3 (HUI-3), EuroQol (EQ-5D), and Short Form 6D (SF-6D)-and a visual analog scale (VAS) for measuring utility scores in women with urge, stress, and mixed urinary incontinence.

Study design: Utility scores were measured in 202 women with urinary incontinence. Pelvic floor symptom severity and quality of life were measured using the Pelvic Floor Distress Inventory and Pelvic Floor Impact Questionnaire, respectively. Construct, discriminant, and concurrent validity were evaluated.

Results: Significant correlations were noted between utility scores and the Pelvic Floor Distress Inventory (r = -0.22 to -0.42, P < .05) and the Pelvic Floor Impact Questionnaire (r = -0.32 to -0.50, P < .05). Mean utility scores were significantly lower for women with urge or mixed incontinence compared to stress incontinence for the EQ-5D (0.71 ± 0.23, 0.73 ± 0.26, and 0.81 ± 0.16, respectively, P = .02) and the SF-6D (0.76 ± 0.12, 0.74 ± 0.12, and 0.81 ± 0.11, respectively, P = .02) but not the HUI-3 or the VAS. There was a clinically important difference in utility scores (>0.03) between women with urge or mixed incontinence as compared to stress incontinence for the HUI-3, EQ-5D, and SF-6D but not the VAS. Utility preference scores were significantly lower for women with combined urinary and fecal incontinence (0.69-0.73) than urinary incontinence alone (0.77-0.84, P < .01).

Conclusion: The HUI-3, EQ-5D, and SF-6D, but not the VAS, provide valid measurements for utility scores in women with stress, urge, and mixed urinary incontinence.

Keywords: EuroQol; Health Utilities Index Mark 3; Short Form 6D; health-related quality of life; urinary incontinence; utility score.