Does Urodynamic Stress Incontinence Increase After the Menopause?: Results from 2,994 Urodynamic Studies in Australian Women

Abstract

Abstract Introduction and Hypothesis Most studies attempting to estimate the age-related prevalence of urinary incontinence (UI) have used questionnaires. In the present study we analysed a consecutive series of urodynamic test results to determine the distribution of the different types of UI in pre- and post-menopausal women. We hypothesised that the prevalence of urodynamic stress incontinence (USI) would be significantly greater in pre-menopausal than in post-menopausal women. Methods All women from a large tertiary urogynaecology department, who underwent urodynamic tests during the years 2000–2015 were included. Patient history and test results were collected. A sample size of 1,475 was calculated, based on the hypothesis that the prevalence of USI will be 20% larger in the pre- versus the post-menopausal group. Results A total of 2,994 women with UI on urodynamics were available. There was a significant difference between pre- and post-menopausal status for each of the three diagnoses: USI 483 (59.3%) versus 912 (41.8%), detrusor overactivity (DO) 125 (15.4%) versus 399 (18.3%) and USI with concomitant DO 206 (25.3%) versus 869 (39.9%). A bimodal pattern of age was seen in women with USI, with a peak in the 46–50 and 61–65 age group, before decreasing with age. DO generally increased with age. USI with concomitant DO increased steadily after the menopause, becoming the predominant type after the age of 66. Conclusions In this large cohort of women attending urodynamics, we have shown that USI is the predominant type of incontinence in pre-menopausal women; however, USI with concomitant DO increases after menopause, eventually predominating.