Basic versus biofeedback-mediated intensive pelvic floor muscle training for women with urinary incontinence: the OPAL RCT

Abstract

Background: Urinary incontinence affects one in three women worldwide. Pelvic floor muscle training is an effective treatment. Electromyography biofeedback (providing visual or auditory feedback of internal muscle movement) is an adjunct that may improve outcomes.

Objectives: To determine the clinical effectiveness and cost-effectiveness of biofeedback-mediated intensive pelvic floor muscle training (biofeedback pelvic floor muscle training) compared with basic pelvic floor muscle training for treating female stress urinary incontinence or mixed urinary incontinence.

Design: A multicentre, parallel-group randomised controlled trial of the clinical effectiveness and cost-effectiveness of biofeedback pelvic floor muscle training compared with basic pelvic floor muscle training, with a mixed-methods process evaluation and a longitudinal qualitative case study. Group allocation was by web-based application, with minimisation by urinary incontinence type, centre, age and baseline urinary incontinence severity. Participants, therapy providers and researchers were not blinded to group allocation. Six-month pelvic floor muscle assessments were conducted by a blinded assessor.

Setting: This trial was set in UK community and outpatient care settings.

Participants: Women aged ≥ 18 years, with new stress urinary incontinence or mixed urinary incontinence. The following women were excluded: those with urgency urinary incontinence alone, those who had received formal instruction in pelvic floor muscle training in the previous year, those unable to contract their pelvic floor muscles, those pregnant or < 6 months postnatal, those with prolapse greater than stage II, those currently having treatment for pelvic cancer, those with cognitive impairment affecting capacity to give informed consent, those with neurological disease, those with a known nickel allergy or sensitivity and those currently participating in other research relating to their urinary incontinence.

Interventions: Both groups were offered six appointments over 16 weeks to receive biofeedback pelvic floor muscle training or basic pelvic floor muscle training. Home biofeedback units were provided to the biofeedback pelvic floor muscle training group. Behaviour change techniques were built in to both interventions.

Main outcome measures: The primary outcome was urinary incontinence severity at 24 months (measured using the International Consultation on Incontinence Questionnaire Urinary Incontinence Short Form score, range 0-21, with a higher score indicating greater severity). The secondary outcomes were urinary incontinence cure/improvement, other urinary and pelvic floor symptoms, urinary incontinence-specific quality of life, self-efficacy for pelvic floor muscle training, global impression of improvement in urinary incontinence, adherence to the exercise, uptake of other urinary incontinence treatment and pelvic floor muscle function. The primary health economic outcome was incremental cost per quality-adjusted-life-year gained at 24 months.

Results: A total of 300 participants were randomised per group. The primary analysis included 225 and 235 participants (biofeedback and basic pelvic floor muscle training, respectively). The mean 24-month International Consultation on Incontinence Questionnaire Urinary Incontinence Short Form score was 8.2 (standard deviation 5.1) for biofeedback pelvic floor muscle training and 8.5 (standard deviation 4.9) for basic pelvic floor muscle training (adjusted mean difference -0.09, 95% confidence interval -0.92 to 0.75; p = 0.84). A total of 48 participants had a non-serious adverse event (34 in the biofeedback pelvic floor muscle training group and 14 in the basic pelvic floor muscle training group), of whom 23 (21 in the biofeedback pelvic floor muscle training group and 2 in the basic pelvic floor muscle training group) had an event related/possibly related to the interventions. In addition, there were eight serious adverse events (six in the biofeedback pelvic floor muscle training group and two in the basic pelvic floor muscle training group), all unrelated to the interventions. At 24 months, biofeedback pelvic floor muscle training was not significantly more expensive than basic pelvic floor muscle training, but neither was it associated with significantly more quality-adjusted life-years. The probability that biofeedback pelvic floor muscle training would be cost-effective was 48% at a £20,000 willingness to pay for a quality-adjusted life-year threshold. The process evaluation confirmed that the biofeedback pelvic floor muscle training group received an intensified intervention and both groups received basic pelvic floor muscle training core components. Women were positive about both interventions, adherence to both interventions was similar and both interventions were facilitated by desire to improve their urinary incontinence and hindered by lack of time.

Limitations: Women unable to contract their muscles were excluded, as biofeedback is recommended for these women.

Conclusions: There was no evidence of a difference between biofeedback pelvic floor muscle training and basic pelvic floor muscle training.

Future work: Research should investigate other ways to intensify pelvic floor muscle training to improve continence outcomes.

Trial registration: Current Controlled Trial ISRCTN57746448.

Funding: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 70. See the NIHR Journals Library website for further project information.

Keywords: BIOFEEDBACK; EMG; EXERCISE THERAPY; PELVIC FLOOR; QUALITATIVE EVALUATIONS; RANDOMISED CONTROLLED TRIAL; STRESS AND MIXED URINARY INCONTINENCE.