Prevalence and Risk Factors for Urinary Incontinence in Nulliparous Women: A Contemporary, Population-Based Cohort Study

Importance and Objectives Epidemiologic studies of incontinence largely focus on parous women, and there are limited data regarding nulliparous women. Our objectives were to evaluate risk factors for urinary incontinence among a nationally representative, contemporary sample of nulliparous women of all ages in the United States and to describe the prevalence and subtypes of urinary incontinence and nocturia in this population. Study Design This cross-sectional, population-based study used the National Health and Nutrition Examination Survey cycles 2011–2018 to assemble a sample of nulliparous women 20–80 years old. Crude and adjusted odds ratios were estimated using multivariable logistic regression for the exposures of interest: body mass index (BMI), age, physical activity, prior hysterectomy, and current smoking. Prevalence of urinary incontinence and nocturia were estimated. Results Among 1,603 nulliparous women, prevalence of any urinary incontinence was 29.38%. Prevalence of stress, urgency, and mixed urinary incontinence and nocturia, respectively, were 27.68%, 19.64%, 10.57%, and 58.95%. Women with a BMI ≥25 (calculated as weight in kilograms divided by height in meters squared; adjusted odds ratio [aOR], 1.57; 95% confidence interval [CI], 1.11–2.23), at least 45 years (aOR, 3.75; 95% CI, 2.31–5.83), and current smoking (aOR, 1.63; 95% CI, 1.07–2.49) had increased the odds of incontinence compared with women without these risk factors. When stress urinary incontinence (SUI) was considered alone, only women with a BMI ≥25 (aOR, 1.66; 95% CI, 1.20–2.31) and age at least 45 years (aOR, 3.17; 95% CI, 2.01–5.00) had increased odds of SUI compared with women without these risk factors. Conclusions Urinary incontinence and nocturia are prevalent in nulliparous women, and age, elevated BMI, and current smoking may represent risk factors for incontinence in this population.