Objective: To estimate how symptom severity, extent of bother, and quality of life differ across urinary incontinence (UI) subtypes.
Methods: We evaluated prevalent UI cases from the Nurses' Health Studies, including women aged 41-83 years. Women with UI (leaking more than once per month) were subclassified according to reported symptoms such as stress UI (SUI, leakage with activity), urge UI (UUI, leakage with urgency), or mixed UI (SUI and UI co-occurring equally). The UI severity was assessed in 102,418 women based on the Sandvik severity index. In a subset of older women with weekly UI, we asked about bother (n=1,697) and quality of life (Incontinence Impact Questionnaire; n=1,748). The UI severity, bother, and quality of life were compared across subtypes using polytomous logistic regression, adjusting for other characteristics.
Results: The distributions of UI subtypes were 51% SUI, 27% UUI, and 22% mixed UI. Approximately half had slight UI, 26% had moderate UI, and 23% had severe UI. Severe UI was more common in women reporting mixed UI (37%) than UUI (27%) or SUI symptoms (15%) (P<.001). More women with severe mixed (21%; P=.02) and UUI symptoms (13%; P=.1) reported being "greatly" bothered by their UI compared with SUI (10%). Women with severe mixed (mean 18.0; P<.001) and UUI symptoms (mean 13.4; P=.004) had higher mean incontinence effect scores compared with SUI (mean 9.8).
Conclusion: Women reporting mixed UI symptoms describe more severe and bothersome incontinence, with higher effect on quality of life.
Level of evidence: II.