Prevalence of urinary incontinence among women and analysis of potential risk factors in Germany and Denmark

Introduction: Urinary incontinence (UI) is a prevalent condition that interferes with women's health-related quality of life. Prevalence rates from earlier studies are wide-ranging, due to heterogeneity in methodology, definition of UI and the populations included. We aimed to determine the prevalence of UI and associated risk factors in Germany and Denmark using the same methodology, definition and population. Material and methods: A postal survey was conducted in two regions in Germany and Denmark, including 8000 women aged 18+ years. UI was defined as any complaint of involuntary loss of urine. The questionnaire contained socio-demographic questions and the International Consultation on Incontinence Modular Questionnaire Urinary Incontinence Short Form (ICIQ-UI SF). Results: The response rate in Germany and Denmark was 46.2 and 66.6% (p < 0.001) and the prevalence rate of UI was 48.3 and 46.4% (p = 0.188), respectively. Stress urinary incontinence dominated among younger women, and urgency urinary incontinence and mixed urinary incontinence among women 80+ years in Germany and Denmark, respectively. The subgroup of women with body mass index (BMI) ≥35 had the highest prevalence of UI (67.3%). The subgroup of women with BMI <35 were more likely to have stress urinary incontinence, and the subgroup of women with BMI ≥35 were more likely to have mixed urinary incontinence. UI was significantly associated with age as with BMI, vaginal delivery, chronic obstructive pulmonary disease, and having at least one co-morbidity. Conclusions: Prevalence rates in the two regions in Germany and Denmark were similar, despite significantly different response rates. This difference may reflect various attitudes towards answering a questionnaire, but the response rate on questions concerning UI seemed consistent.