Prevalence and risk factors of urinary incontinence in young and middle-aged women.

Objective To assess the prevalence of and risk factors for urinary incontinence (UI) in young and middle-aged women. Subjects and methods During 1998 the prevalence of overall, stress, urge and mixed UI was assessed in women working in a French academic hospital. Women (2800) received a questionnaire at the same time as their yearly interview with a staff physician in occupational medicine. The usual risk factors for constitutional events, i.e. increasing age, obesity (defined as a body mass index of > or = 25), obstetric events (pregnancy, previous Caesarean delivery, previous vaginal delivery, postpartum incontinence) and gynaecological events (hysterectomy) were evaluated. Results Of the 1700 women (mean age 40.0 years) who returned the questionnaire, 467 (27.5%, 95% confidence interval, CI, 25.4-29.7) reported UI, comprising 210 (12.4%, 10.8-14.0) with stress UI, 28 (1.6%, 1.1-2.4) with urge UI and 229 (13.5%, 11.9-15.2) with mixed UI. Thirty-eight women (8.1%) had frequent urinary leakage, comprising one (0.5%), four (14.3%) and 33 (14.4%) with stress, urge and mixed UI. The prevalence of UI increased significantly with age > or = 40 years, with a relative risk (95% CI) of 2.16 (1.86-2.57), and with pregnancy (2.22, 1.71-2.87), previous vaginal delivery (2.15, 1.72-2.69), postpartum incontinence (2.57, 2.22-2.97), and hysterectomy (1.52, 1.11-2.08). Obesity (1.14, 0.99-1.32) and previous Caesarean delivery (2.15, 1.72-2.69) did not significantly increase the risk of UI. The risk factors for stress UI were age > or = 40 years, pregnancy, previous vaginal delivery, postpartum incontinence and hysterectomy, but there was no relationship between stress UI and obesity or previous Caesarean delivery. Conclusion There was a high prevalence of UI among young adult and middle-aged women hospital workers who had easy access to medical resources. Gynaecological and obstetric events (pregnancy, particularly previous vaginal delivery and hysterectomy) were the most prominent risk factors, especially for stress UI.