Objective: To examine the impact of each type of urinary incontinence (stress, urge, and mixed) on health-related quality of life (HRQL).
Subjects and methods: The USA National Overactive Bladder Evaluation (NOBLE) programme of prevalence was used to identify respondents with incontinence based upon telephone survey responses. A nested case-control study was then conducted on respondents with symptoms of an overactive bladder (OAB), and on age and gender-matched controls; this consisted of the respondents completing a series of questionnaires, including the OAB-q (an HRQL scale for OAB), the Medical Outcomes Study (MOS) Short-Form-36 (SF-36), the MOS Sleep Scale, and the Center for Epidemiological Studies - Depression (CES-D) scale. Respondents were categorized into subgroups according to the primary cause of urine loss, i.e. sudden/uncomfortable urge to urinate (urge, UI), physical pressure (stress, SI), or both (mixed, MI). Descriptive analyses, t-tests and analysis of variance with post hoc comparisons were used.
Results: Of the 919 participants in the nested case-control study, 171 reported incontinence, i.e. UI (69), SI (62) and MI (40). Among this cohort, 82.5% were female, 85.4% were Caucasian and the population had a mean age of 55.9 years. All OAB-q subscale scores were significantly (P < 0.01) worse among those with MI than with SI. Respondents with UI reported significantly higher levels of symptom bother and lower sleep scores (both P < 0.001) than those with SI. There were no differences in HRQL between the MI and UI groups. Voiding frequency and nocturia episodes did not differ among the groups but compared with the SI group, both UI and MI groups reported significantly higher ratings of urinary urge intensity (P < 0.001) and rated their need for medical care significantly higher (P < 0.01). The MI group reported more incontinence episodes (P = 0.02) than the SI group.
Conclusion: Compared with SI, respondents with UI and MI reported not only significantly greater ratings of urinary urge intensity and more incontinence episodes, but also significantly worse HRQL. These results are consistent with previous findings which indicated a greater impact on HRQL for the urge component of MI than for the stress component.