Objective: The purpose of this study was to identify risk factors for urinary incontinence in middle-aged women.
Study design: We conducted a cross-sectional analysis of 83,355 Nurses' Health Study II participants. Since 1989, women have provided health information on mailed questionnaires; in 2001, at the ages 37 to 54 years, information on urinary incontinence was requested. We examined adjusted odds ratios of incontinence using logistic regression.
Results: Forty-three percent of the women reported incontinence. After adjustment, black (odds ratio, 0.49; 95% CI, 0.40-0.60) and Asian-American women (odds ratio, 0.57; 95% CI, 0.46-0.72) were at reduced odds of severe incontinence compared with white women. Increased age, body mass index, parity, current smoking, type 2 diabetes mellitus, and hysterectomy all were associated positively with incontinence. Women who were aged 50 to 54 years had 1.81 times the odds of severe incontinence compared with women who were <40 years old (95% CI, 1.66-1.97); women with a body mass index of > or =30 kg/m2 had 3.10 times the odds of severe incontinence compared with a body mass index of 22 to 24 kg/m2 (95% CI, 2.91-3.30).
Conclusion: Urinary incontinence is highly prevalent among these middle-aged women. Potential risk factors include age, race/ethnicity, body mass index, parity, smoking, diabetes mellitus, and hysterectomy.