Background Pelvic floor muscle (PFM) training (PFMT) is a common conservative first-line
treatment for SUI in women. However, the success of PFMT alone, without adjunctive
therapies, has been hampered by the lack of training adherence among patients, who report
the inability to contract the correct PFMs and limited motivation to perform PFMT
exercises. Therefore, PFMT is often combined with adjunctive therapies, such as
electromyography (EMG) biofeedback via an intravaginal probe (referred to as conventional
biofeedback), transvaginal electrical stimulation (TVES), or weighted vaginal cones.
However, PFMT adjunctive therapies that involve intravaginal probes/ cones are not
preferred by women because they are invasive, and the vaginal insertion of probes/ cones
can cause pain and discomfort. In addition, older women with atrophic vaginas have
difficulty retaining probe/cones within the vaginal canal due to weak PFM tone.
To meet the existing need for a non-invasive PFMT adjunctive therapy, the research team
developed the PelviSense. The PelviSense is an innovative, non-invasive biofeedback
device with wearable EMG sensors, designed to assist individuals in isolating and
strengthening PFMs by helping them distinguish correct PFM contractions (lifting or
squeezing the muscles) from incorrect attempts (bearing down). A mixed-methods study,
including a full-scale RCT and semi-structured focus groups, alongside an economic
evaluation, will be conducted to evaluate both the effectiveness and cost-effectiveness
of the newly developed PelviSense device for the treatment of SUI in women.
Aims:
Aim 1: Investigate the efficacy of PelviSense-assisted PFMT compared with PFMT alone for
improving SUI symptom severity in women.
Aim 2: Compare the cost-effectiveness of the PelviSense device against PFMT alone for
treating SUI in women.
Aim 3: Explore the views of women regarding the use of the PelviSense device as an
adjunct to PFMT and the impacts of the PelviSense device on their lives and well-being.
Methods Recruitment: Women with SUI who attend the outpatient Obstetrics and Gynecology
Department of Kwong Wah Hospital (KWH) will be recruited for the study. In addition,
potential participants will be recruited using a non-probability convenience sampling
technique through public, KWH, elderly care centers, and HK Polytechnic University
(PolyU) campus advertising. Advertising will consist of study flyers posted at KWH,
around the university campus, in waiting rooms of university health services and
physiotherapy clinics, in community churches, and in university-owned amenities,
including sports centres and gyms.
Randomisation and blinding: Computer-generated randomisation will be utilised to ensure
that both study groups are assigned an equal number of participants at a 1:1 ratio.
Sequentially numbered, sealed, opaque envelopes of similar size and shape will be
utilised to conceal group allocation and avoid selection bias. Due to the nature of the
intervention, it is not possible to blind the therapists or participants to the
allocation of treatment; therefore, only the outcome assessor will be blinded. To
minimise detection bias, the outcome assessors will not participate in the treatment, and
all study outcomes will be assessed in a separate room without any knowledge of
participant allocation. Statistical analysis will be performed in a blinded manner, with
each group assigned a code (group A and group B). The group identities will be revealed
after all analyses are completed.
Procedure and baseline assessment: Potentially eligible women who contact research
personnel will be invited to attend an in-person screening session. On this first day of
contact, all women will undergo BMI measurement; complete the screening questionnaire,
MMSE, and 1-h pad test to confirm eligibility; and provide written informed consent.
Baseline assessments of study outcomes will be performed, and eligible and consenting
participants will be randomised to intervention groups.
Outcome measures Outcomes assessments will be completed at baseline (time point 1 [T1]),
1-month (T2) and 6-months (T3).
Intervention. The interventions will be provided for 6 months, beginning with a 1-month
supervised training period at KWH and PolyU. Following supervised training, women will be
instructed to perform unsupervised home exercises for 5 months. Unsupervised home
exercises will consist of at least eight contractions, performed 3 times per day, for 5
days of each week, with or without the biofeedback device according to group assignment.
Each contraction will last for 10 seconds, followed by relaxation for 10 seconds. The
PFMT exercise parameters are based on the National Institute for Health and Care
Excellence PFMT guidelines for UI.
Qualitative study (semi-structured focus groups). A computer-generated randomization
schedule will be utilized to identify 20 participants (from the 71 participants included
in the PelviSense-assisted PFMT group) to participate in the focus groups. Each focus
group will last for 45-60 minutes. Focus groups will continue to be conducted until data
saturation occurs. Focus groups will be scheduled for 8-months post-randomisation. A
semi-structured focus group approach will be used, during which discussion will be guided
by but not limited to a set of pre-determined, open-ended questions.
Data processing and analysis: Statistical analysis will be performed on an
intention-to-treat basis using the Statistical Package for the Social Sciences (v.25;
Armonk, NY).
Treatment effects for both primary and secondary outcomes between T1, T2, and T3 and
across the intervention groups will be evaluated using a two-way analysis of covariance
(ANCOVA) with age as the covariate. T1 and T2 will be compared to establish immediate
treatment effects, and T1 and T3 will be compared to evaluate the retention of treatment
effects. For significant group by time interaction effects, post-hoc analysis using
Bonferroni correction will be performed.
The unadjusted mean total and disaggregated costs and differences in costs between the
PelviSense and PFMT alone groups will be calculated. Seemingly unrelated regression (SUR)
analyses will be used to estimate total cost differences (ΔC) and effect differences
(ΔE).
The EQ-5D-5L responses will be converted into utility scores to estimate the gain or loss
of quality-adjusted life-years (QUALYs). The incremental cost-effectiveness ratio (ICER)
will be calculated using the formula ICER = ΔC / ΔE. Uncertainty surrounding ICERs and
95% confidence intervals for cost differences will be estimated using bias-corrected and
accelerated bootstrapping with 5,000 replications.
Qualitative data from the focus groups will be analysed using the six phases of thematic
analysis recommended by Braun and Clarke. The identified themes will then be defined and
named according to their contents. The final set of themes will be confirmed as coherent
and comprehensive by review of the team.