Mixed urinary incontinence (UI) is, on average, more severe than urgency UI or stress UI. We tested the hypothesis that mixed UI is a more advanced stage of UI by comparing transition probabilities among women with stress, urgency, and mixed UI.
We used data from the General Longitudinal Overactive Bladder Evaluation Study-UI, which included community-dwelling women, aged 40+ years, with UI at baseline. Study participants completed two or more consecutive bladder health surveys every 6 months for up to 4 years. Using sequential 6-month surveys, transition probabilities among UI subtypes were estimated using the Cox-proportional hazards model, with the expectation that probabilities from stress or urgency UI to mixed UI would be substantially greater than probabilities in the reverse direction.
Among 6,993 women 40+ years of age at baseline, the number (prevalence) of women with stress, urgency, and mixed UI was 481 (6.9%), 557 (8.0%), and 1488 (21.3%) respectively. Over a 4-year period, the transition probabilities from stress UI (34%) and urgency UI (27%) to mixed UI was significantly higher than probabilities from mixed to stress UI (6%) or to urgency UI (rate = 9%). The adjusted transition hazard ratio for stress UI and urgency UI was 2.06 (95% CI: 1.73-2.92) and 1.85 (95% CI: 1.63-2.57) respectively compared with mixed UI.
The substantially higher transition from stress UI and urgency UI to mixed UI supports the hypothesis that mixed UI might represent a more advanced stage of UI that may have implications for understanding disease progression.
International urogynecology journal. 2018 Mar 13 [Epub ahead of print]
Vatché A Minassian, Xiaowei Yan, Anna L Pilzek, Raisa Platte, Walter F Stewart
Department of Urogynecology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA, 02115, USA. ., Sutter Research, Development & Dissemination, Sutter Health System, Walnut Creek, CA, USA., Center for Health Research, Geisinger Health System, Danville, PA, USA., Spectrum Health, Grand Rapids, MI, USA.