Study finds significant association between age and OAB

This study underscores how common urinary incontinence is in women, with nearly 1 in 5 Japanese women reporting urinary incontinence related to OAB or SUI in the last month,” said Stephanie Faubion, MD, MBA, medical director of the North American Menopause Society.

An analysis of cross-sectional data from the Japan Nurses’ Health Study (JNHS) found that patients with overactive bladder (OAB) were significantly associated with postmenopausal status and an age group of 45 to 54 years.1

Investigators also reported that obesity and the number of times a woman has given birth were associated with a higher risk for stress urinary incontinence (SUI).

The prospective JNHS began collecting data from female nurses in 2001, in which participants answered a questionnaire gathering information on several factors, such as demographics and physical condition, to analyze long-term data in this cohort.2 Data have been collected every 2 years since baseline from a participant population of 15,019.

In this new study, conducted in the School of Health Sciences at Gunma University, Japan, OAB, SUI, and mixed urinary incontinence (MUI) were evaluated among the female nurse population. JNHS participants were excluded from the study if they did not answer questions about urinary symptoms or were pregnant, which left 12,198 participants to be included in the final analysis.

“This study underscores how common urinary incontinence is in women, with nearly 1 in 5 Japanese women reporting urinary incontinence related to OAB or SUI in the last month,” said Stephanie Faubion, MD, MBA, North American Menopause Society medical director, in a recent news release.3

To define OAB, SUI, and MUI, the participants chose the quotes that best matched their experience, according to a video accompanying the study. If they selected, “I experience urine leakage when coughing or moving my body,” they were deemed to have SUI. If they selected, “I am unable to wait to urinate and I have experiences urine leakage,” they were deemed to have OAB-wet. If they selected, “I suddenly need to urinate and it has been difficult to wait,” they were deemed to have OAB-dry. Participants were deemed to have MUI if they chose a combination of responses.

All of the participants in this study were at least 25 years of age and lived in Japan at baseline. The mean age of this cohort was 46.5 years (SD +/- 8.1, range 27-82), and the mean body mass index (BMI) was 22.1 kg/m2 (SD +/- 3.1, range 12.9-44.6).

Odds ratios with 95% confidence intervals were used to calculate the odds of OAB, SUI, and MUI. The prevalence of urinary symptoms was also calculated and compared among different age groups.

The investigators found that the prevalence of OAB-wet was 5.4%; OAB-dry, 4.1%; SUI without OAB-wet, 13.9%; and MUI, 2.1%. In addition to the association between OAB, age 45 to 54 years, and postmenopausal status, analysis showed that SUI without OAB-wet was significantly associated with age groups 45 to 49 and 50 to 54, BMI 23 to 27.4 and 27.5 kg/m2 or higher, and parous status.

“Midlife women were particularly affected by SUI (18.2% in women aged 50 to 54 years),” continued Faubion. “Given the significant negative effect on quality of life and the presence of effective strategies for management of these burdensome symptoms, clinicians should routinely ask women about urinary incontinence.”

In the concluding remarks of a presentation summarizing the study’s findings, co-author Kazue Nagai, PhD, said, “We plan to carry out prospective evaluation of urinary symptoms in a future study because we could not examine improvements in urinary symptoms over time in the present study.”


1. Nagai K, Homma Y, Ideno Y, Hayashi K. Prevalence and factors associated with overactive bladder and stress urinary incontinence in the Japan Nurses’ Health Study. Menopause. Published online November 12, 2021. doi:10.1097/GME.0000000000001893

2. Hayashi K, Mizunuma H, Fujita T, et al. Design of the Japan Nurses’ Health Study: A prospective occupational cohort study of women’s health in Japan. Ind Health. 2007 Oct;45(5):679-86. doi:10.2486/indhealth.45.679.

3. Overactive bladder and urinary incontinence worsen with age. News release. The North American Menopause Society. December 15, 2021. Accessed January 11, 2022.