Prevalence, incidence and remission of urinary incontinence in women: longitudinal data from the Norwegian HUNT study (EPINCONT)

Abstract

To determine incidence and remission of UI as well as changes in UI prevalence in the Norwegian EPINCONT surveys. The EPINCONT surveys were conducted in the county of Nord-Trøndelag, Norway, as part of two large cross-sectional health surveys (HUNT2 and HUNT3) in 1995 – 1997 (EPINCONT1 (E1)), and 2006 – 2008 (EPINCONT2 (E2)). EPINCONT collected information about prevalence of UI, as well as information about type and severity of UI. A 16% relative increase in UI prevalence was found in 11 years. The women who answered E2 were significantly older, had a higher BMI and higher prevalence of diseases such as asthma, diabetes and angina compared with the women who answered E1. The incidence of UI was 18.7%. Increase in BMI (OR 1.03, 95% CI: 1.02 – 1.04), weight increase (OR 1.29 (95% CI: 1.14 – 1.45) for gaining 3 – 10 kilos and OR 1.71 (95% CI: 1.47 – 1.99) for gaining 10 kilos or more) and parity (OR 1.37 (95% CI: 1.04 – 1.79) for 1 childbirth, OR 1.28 (95% CI: 1.03 – 1.61) for 2 childbirths, and OR 1.56 (95% CI: 1.26 – 1.95) for 3 or more childbirths when participating in E2) were all found to be associated with increased odds of incident UI in adjusted regression analyses. Increasing age reduced the odds of incident UI. The 11 year remission of UI was 34.1%. Increasing age (OR 0.98, 95% CI: 0.98 – 0.99), increasing BMI (OR 0.96, 95% CI: 0.95 – 0.98) and large weight gains of 10 kilos or more (OR 0.69, 95% CI: 0.54 – 0.88) were all associated with reduced remission of UI. Crude UI prevalence increased between the studies. Changes in known risk factors for UI such as age, BMI, weight and parity could explain some of the relative increase in prevalence, and were also found to be associated with either incidence of UI, remission of UI or both.