To assess whether urinary incontinence and its severity are associated with the International Prostate Symptom Score (IPSS) in Japanese women using linguistically validated questionnaires.

Using a self-administered questionnaire of the IPSS and the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF), lower urinary tract symptoms were evaluated in a consecutive series of 1634 women (mean age 48.1 years) who underwent multiphasic health screening at our institution. Ordinal logistic regression analysis was applied, with age, ICIQ-SF, and continence status as the explanatory variable and IPSS severity as the response variable.

All scores, including the IPSS (with its voiding and storage symptom scores) and the ICIQ-SF, were significantly greater for the incontinent than the continent women and for those with urge and mixed incontinence than those with stress incontinence. Including all women, IPSS severity was significantly associated with age (odds ratio [OR] 1.03), ICIQ-SF (OR 1.22), and urge (OR 2.79) and mixed (OR 3.54) incontinence, but not with stress incontinence. Among women with stress incontinence, however, the IPSS severity was significantly associated with the ICIQ-SF (OR 1.21), but not with age.

Not only continence status, but also its severity (ICIQ-SF score), has a significant impact on IPSS. We, therefore, must be cautious about interpreting the epidemiologic data on female lower urinary tract symptoms without simultaneous quantitative assessment of urinary incontinence with a validated instrument.