The effect of hysterectomy or levonorgestrel-releasing intrauterine system on lower urinary tract symptoms: a 10-year follow-up study of a randomised trial

Objective To evaluate the effect of hysterectomy and levonorgestrel-releasing intrauterine system (LNG-IUS) on lower urinary tract symptoms (LUTS) among women treated for menorrhagia. Design Randomised controlled trial analysed by actual treatment. Setting Five university hospitals in Finland. Sample A cohort of 236 women, aged 35-49 years, referred for menorrhagia between 1994 and 1997. Methods Women were randomly assigned to treatment by hysterectomy (n = 117) or LNG-IUS (n = 119). Main outcome measures Lower urinary tract symptoms were evaluated by questionnaires at baseline, and after 6, 12 months, 5, and 10 years. Medications and operations for urinary incontinence were confirmed from medical records and national registries. Results Overall, 221 (94%) women took part in the 10-year follow-up evaluation. As 55 (46%) women originally randomised to the LNG-IUS group underwent hysterectomy, the results were analysed by actual treatment. Women treated by hysterectomy used more medication for urinary incontinence than LNG-IUS users (12% versus 1%) (OR 9.45, 95% CI 1.24-71.87, P = 0.006). Three hysterectomised women and one LNG-IUS user underwent surgery for stress urinary incontinence (SUI). Women treated by hysterectomy had more urinary tract infections (UTIs) than LNG-IUS users (OR 3.20, 95% CI 1.47-6.96, P = 0.002). Feeling of incomplete emptying (OR 3.00, 95% CI 1.00-9.05, P = 0.04) and SUI (OR 1.83, 95% CI 1.01-3.32, P = 0.04) were more common among women treated by hysterectomy. No differences between the study arms were noted in urge urinary incontinence or by the Urinary Incontinence Severity Score. A multivariate model showed that UTIs were associated with hysterectomy (P = 0.004). Conclusions Hysterectomy increases the risks for incomplete emptying, lower UTIs and SUI.