Multicentre randomised trial of the effectiveness and cost-effectiveness of basic versus biofeedback-mediated intensive pelvic floor muscle training for female stress or mixed urinary incontinence (OPAL-Optimal PFMT for Adherence Long-term)

DESIGN: •A multicentre, 2-arm randomised controlled trial to compare effectiveness and cost-effectiveness of basic PFMT versus biofeedback-mediated intensive PFMT, with a mixed-methods, nested process evaluation. •An interview study (two-tailed case study) with purposively selected women from both trial arms to explore experience and adherence. SETTING: UK community and outpatient settings where women are referred for the treatment of UI. To date, 14 centres we have collaborated with previously have agreed in principle to recruit. TARGET POPULATION: Women >=18 years with a new episode of stress or mixed UI. Excluded are those who: have urge UI only; have had formal PFMT or UI surgery in the last 3 years; are pregnant or stage II, pelvic cancer, cognitive impairment or neurological disease; are taking antimuscarinics (unless discontinued for 6 weeks). HEALTH TECHNOLOGIES BEING ASSESSED: 1) Basic PFMT (6 appointments at weeks 0,1,3,6,10,15); 2) intensive PFMT (same appointments as basic PFMT, with use of biofeedback at all appointments, and home biofeedback during weeks 1-15). PFMT is the repetitive contraction of the pelvic floor muscles, to improve muscle function and ultimately continence. A therapist assesses the muscles and prescribes exercises; increasing repetitions, lengthening contractions and reducing rest periods over time. National guidelines recommend at least 3 month’s of PFMT as treatment for stress UI; average of 6 appointments. Basic PFMT is defined here as 6 appointments over 16 weeks, in line with recent evidence indicating that at least 15 weeks is needed to achieve muscle hypertrophy [American College of Sports Medicine 2011]. Biofeedback is the feedback of information to a woman so that she can identify and modify the action of her pelvic floor muscles. A vaginal probe measures electrical activity during muscle contraction (EMG) which is displayed on a screen. The woman uses this information as confirmation of correct contraction technique (teaching); to increase strength or timing of contractions (modulating); and to improve exercise adherence (encouraging). In the intensive PFMT arm, in addition to basic PFMT, EMG biofeedback is used at each appointment to teach, modulate and encourage; and home EMG biofeedback to reinforce and encourage effective exercising between appointments (weeks 1-15). No biofeedback equipment will be used in the basic PFMT arm. Verbal feedback during digital palpation will be permitted in both trial arms. A women's health physiotherapist or continence nurse will deliver the PFMT interventions. The proposed mechanism of action is that biofeedback will increase women’s self-efficacy for PFMT and hence their adherence, leading to improved treatment outcomes. MEASUREMENT OF COST AND OUTCOMES: • Primary outcome: UI severity at 24 months (ICIQ-UI score [Avery 2004]–leakage frequency/amount/interference, scored 0-21). • Secondary outcomes: number of episodes of UI per day (recorded by women in a leakage diary), number with cured/improved UI, other urinary symptoms (ICIQ-FLUTS), UI-specific quality of life (ICIQ-UIqol), self-efficacy for PFMT (PFME self-efficacy scale), impression of global improvement in UI (PGI-I), adherence to exercise, uptake of surgery and other UI treatment, pelvic floor muscle function. Data will be collected via participant-completed postal questionnaires at baseline, 6, 12 and 24 months. At baseline and 24 months: recording of leakage episodes and PFMT adherence by women in daily diaries. At baseline and 6 months: blinded assessment of pelvic floor muscle function to quantify muscle change. • Primary health economic outcome: incremental cost per quality adjusted life year gained at 24 months. EQ-5D responses will be used to estimate QALYs, then the incremental cost-effectiveness ratio for 24 month follow-up. Sensitivity analyses will take into account any uncertainties. Secondary economic outcomes: resource use and costs to the NHS, women and their families; EQ-5D scores over 24 months. Cost and QALY outcomes will be extrapolated over a woman’s lifetime if there are significant differences between trial arms.