Previous studies have shown an association between urinary incontinence (UI) and increased mortality, independent of demographics and health status. However, they do not account for the effect of frailty, as a state of vulnerability. We evaluated whether there was an association between UI and mortality, and if so, whether adjustment for a frailty index affects the association.
We conducted a cross-sectional study using a nationally representative sample of 2,282 community dwelling individuals ≥50 years surveyed between 2003-2006. The primary outcome was overall survival reported on December 31, 2011. We used design-adjusted Cox proportional hazards regression models to estimate the hazard of mortality associated with UI. We adjusted the models for demographics and a validated 45-item frailty index, incorporating an accumulation of deficits in the domains of health and independence.
23% of individuals reported having UI at least a few times a week. Stress UI and Urge UI were associated with a 13.3% (95%CI 7.2-19.7%) and 18.4% (95%CI 8.3-29.4%) increase in the frailty index. Without controlling for frailty, individuals with UI experienced a higher risk of death (HR=1.39; 95%CI 1.13-1.72). When adjusted for the frailty index, the association between UI and mortality was no longer significant (HR=1.10; 95%CI 0.89-1.36).
The association between UI and mortality can be understood based on increased frailty in incontinent individuals. Urinary incontinence itself is not independently associated with mortality. In clinical practice, these findings underscore the importance of screening for frailty in addition to urinary incontinence.
The Journal of urology. 2019 Oct 03 [Epub ahead of print]
Rano Matta, Amanda E Hird, Refik Saskin, Sidney B Radomski, Lesley Carr, Ronald T Kodama, Robert K Nam, Sender Herschorn
Division of Urology, University of Toronto, Toronto, Ontario, Canada., IC/ES, Toronto, Ontario, Canada.