Sociodemographic Disparities and Parity in Relation to Urinary Incontinence: A Nationwide Primary Healthcare Cohort Study (1997–2018)

Objectives: Urinary incontinence (UI) is a very common condition in the primary healthcare settings. Few studies have investigated whether sociodemographic factors are related to UI. This nationwide study aimed to investigate whether there is a relationship between sociodemographic factors and UI in women. Methods: A nationwide open cohort study included 2,044,065 women aged 15–50 years. Several national population-based (Sweden) databases including nationwide primary healthcare data were used. The outcome was the time to the first event of any UI diagnosis during the study period (1997–2018). Cox regression models were used to test for associations between individual sociodemographic factors and UI. Results: The study identified 44,250 UI events. These corresponded to 2.16% of the study population and an incidence rate (IR) per 1000 person-years of 1.85 (95% CI 1.84–1.87). In the fully adjusted model, a high age, low education level, and being born outside of Sweden were independently associated with a higher UI risk, while rural living was associated with a lower risk. The income level did not seem to have a large impact. Most notably, women born in the Middle East/North Africa and Latin America/Caribbean had a substantially higher risk of UI with HRs of 2.41 (95% CI 2.33–2.49) and 2.30 (95% CI 2.17–2.43), respectively. Parity was strongly and independently associated with UI. Conclusion: This study presents novel risk factors associated with UI. The findings provide new knowledge concerning the burden of this disease among women, which could be used to provide more equal healthcare for these patients in the future. Previous research allied with these findings suggests using a comprehensive approach targeting health disparities.