A Prospective Study of the Natural History of Urinary Incontinence in Women

Symptoms of urinary incontinence are commonly perceived to vary over time; yet, there is limited quantitative evidence regarding the natural history of urinary incontinence, especially over the long-term.

To delineate the course of urinary incontinence symptoms over time, using two large cohorts of middle-age and older women, with data collected over 10 years.

We studied 9,376 women from the Nurses' Health Study, age 56-81 years at baseline, and 7,491 women from Nurses' Health Study II, age 39-56 years, with incident urinary incontinence in 2002-3. Urinary incontinence severity was measured by the Sandvik severity index. We tracked persistence, progression, remission, and improvement of symptoms over 10 years. We also examined risk factors for urinary incontinence progression using logistic regression models.

Among women age 39-56 years, 39% had slight, 45% had moderate, and 17% had severe urinary incontinence at onset. Among women age 56-81 years, 34% had slight, 45% had moderate, and 21% had severe urinary incontinence at onset. Across ages, most women reported persistence or progression of symptoms over follow-up; few (3-11%) reported remission. However, younger women and women with less severe urinary incontinence at onset were more likely to report remission or improvement of symptoms. We found that increasing age was associated with higher odds of progression only among older women (age 75-81 versus 56-60 years, odds ratio=1.84, 95% confidence interval: 1.51, 2.25). Among all women, higher body mass index was strongly associated with progression (younger women: odds ratio=2.37, 95% confidence interval: 2.00, 2.81 body mass index ≥30 vs. < 25 kg/m2; older women: odds ratio=1.93, 95% confidence interval: 1.62, 2.22). Additionally, greater physical activity was associated with lower odds of progression to severe urinary incontinence (younger women: odds ratio=0.86, 95% confidence interval: 0.71, 1.03, highest vs. lowest quartile of activity; older women: odds ratio=0.68, 95% confidence interval: 0.59, 0.80).

Most women with incident urinary incontinence continued to experience symptoms over 10 years; few had complete remission. Identification of risk factors for urinary incontinence progression, such as body mass index and physical activity, could be important for reducing symptoms over time.

American journal of obstetrics and gynecology. 2018 Feb 06 [Epub ahead of print]

Kaitlin A Hagan, Elisabeth Erekson, Andrea Austin, Vatche A Minassian, Mary K Townsend, Julie Pw Bynum, Francine Grodstein

Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA; Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA. Electronic address: ., Department of Obstetrics and Gynecology at the Geisel School of Medicine at Dartmouth, Hanover, NH; Dartmouth Institute for Health Policy and Clinical Practice at the Geisel School of Medicine at Dartmouth, Hanover, NH., Dartmouth Institute for Health Policy and Clinical Practice at the Geisel School of Medicine at Dartmouth, Hanover, NH., Division of Urogynecology, Department of Obstetrics and Gynecology, Brigham and Women's Hospital, Boston, MA., Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA., Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA; Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA.