Prevalence of urinary incontinence among nulliparous women and its association with underweight body mass index: a secondary analysis of a nationwide cross-sectional study in China.

OBJECTIVES

To estimate the prevalence of urinary incontinence (UI) and its subtypes among nulliparous Chinese women with associated risk factors. The prevalence of UI among those living in urban or rural communities was also analysed with potential risk factors.

DESIGN

This is a secondary analysis of epidemiological survey data on UI in Chinese women. The original study was designed as a nationwide cross-sectional study involving 56 460 adult women conducted from October 2019 to December 2021.

SETTING

Seven geographic regions of China.

PARTICIPANTS

Nulliparous women who were aged ≥20 years old and were permanent residents were included in this secondary analysis. Participants who had severe mental or physical disorders or were pregnant were excluded. Data on demographic characteristics, health status and medical history were collected.

PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was the prevalence of UI, whereas secondary outcome measures were adjusted odds ratios (aOR) for risk factor analysis.

RESULTS

A total of 6244 nulliparous women were included in the analysis. The prevalence of UI was 1.9% for nulliparous Chinese women, with stress, urgency and mixed UI being prevalent at 0.9%, 0.3% and 0.7%, respectively. The prevalence of UI was 2.1% and 1.6% for urban and rural subgroups. Abnormal body mass index was significantly associated with UI in the nulliparous group (underweight, aOR: 1.88, 95% CI: 1.03 to 3.45, p=0.041; overweight, aOR: 2.26, 95% CI: 1.37 to 3.73, p=0.001; and obesity, aOR: 3.64, 95% CI: 1.86 to 7.15, p<0.001) and the subgroup in urban areas (underweight, aOR: 2.43, 95% CI: 1.18 to 5.00, p=0.016; overweight, aOR: 3.31, 95% CI: 1.76 to 6.25, p<0.001; and obesity, aOR: 4.53, 95% CI: 1.88 to 10.92, p<0.001); however, no significant association was found for those in rural areas.

CONCLUSION

UI among nulliparous women deserves greater public attention. Abnormal body mass index, including underweight status, was found to be a risk factor for UI among Chinese nulliparous women. Further research is required to investigate the mechanism underlying the association between underweight status and UI.

ETHICS AND DISSEMINATION: The study was approved by Peking Union Medical College Ethics Committee (No. S-K970) and conducted according to the Declaration of Helsinki. All participants signed consent forms before data collection. A completed STROBE checklist detailing compliance with all 22 items is provided.