Female Urgency, Trial of Urodynamics as Routine Evaluation (FUTURE study); a superiority randomised clinical trial to evaluate the effectiveness and cost effectiveness of invasive urodynamic investigations in management of women with refractory overactive bladder symptoms

Background: There is a clear uncertainty on whether invasive Urodynamics investigations improve the treatment outcomes in women with refractory overactive bladder (OAB). Aim: To assess the clinical and cost-effectiveness of routine Urodynamics over and above comprehensive clinical assessment only in women being considered for invasive treatments for refractory OAB. Design & Sample size: A pragmatic superiority RCT. Clinicians and PPI established that a minimum superiority margin of 10% improved patient-reported outcomes is required for the NHS to adopt routine Urodynamics in patients being considered for invasive treatments for refractory OAB. Previous evidence showed patient-reported success rate of ~ 60% following treatments irrespective of Urodynamics diagnosis. So for 90% power and a 5% level of significance, 986 participants are needed, rising to 1096 (or 548/group) to allow for 10% attrition at 15 months post randomisation. An internal pilot phase will establish the feasibility of our recruitment projection with clear stop/go criteria. Eligible participants are women aged >18 years, who are being considered for invasive treatment for refractory OAB. Women would have failed conservative (pelvic floor exercise/ behavioural therapy) and pharmacological treatment (2 different drugs). Women with mixed urinary incontinence will be included if OAB symptoms are the most bothersome Assessment: Participants will undergo a baseline assessment including completion of validated symptom severity and quality of life (QoL) questionnaires; 3-day bladder diary and a bladderscan. Participants will be randomised to undergo either comprehensive clinical assessment only versus comprehensive clinical assessment and Urodynamics. In both study arms, participants will be offered evidence-based treatments for refractory OAB, in line with the NICE guideline and as per the defined treatment pathways. Setting: > 40 secondary and tertiary care hospitals have agreed to participate. We will use a regional hubs structure to enhance recruitment and facilitate study management. Study Duration: 93 months The primary outcome measure is the patient-reported success at 15 months post-randomisation as measured by the Patient Global Impression of Improvement; a robust and validated tool in assessment of treatment outcomes of refractory OAB. The primary economic outcome will be the incremental cost per quality adjusted life year (QALY) gained of Urodynamics compared to comprehensive clinical assessment only - modelled over the lifetime of the patients. The secondary outcomes include improvement in OAB symptoms as assessed by ICIQ-OAB questionnaire; objective reduction of urgency/ urgency incontinence episodes on the bladder diary; health-related QoL profile derived from EQ-5D-5L and ICIQ-LUTSqol; adverse events and further treatments received up to 5-years since they joined the trial. We aim to explore the clinical and cost-effectiveness of different sequence of treatments. A robust protocol for standardisation of Urodynamic practice across the collaborating units has been developed according to the ICS Good Urodynamics Practice. A Qualitative study is embedded within the RCT whose main objectives is to explore: 1. Participants’ attitudes to invasive testing and expected outcomes (prior to randomisation or knowing their allocated study group); 2. Participants’ attitudes to potential treatment options (prior to randomisation or knowing their allocated study group); 3. Participants’ experience of Urodynamics and opinions regarding treatment outcome to include evaluation of treatment satisfaction or desire for further treatment (3 to 6 months post treatment; 4. Surgeon attitudes to the influence of Urodynamics on decision making (at start of the study and 6 to12 months after starting recruitment at their sites).