Hypothesis / aims of study
The use of biofeedback to improve pelvic floor muscle training (PFMT) effectiveness is equivocal [1]. However, no device has provided comprehensive biofeedback on technique (i.e primarily due to activation of pelvic floor muscle (PFM), or other muscles?) nor simultaneous feedback on intra-abdominal pressure (IAP) and PFM pressure. The femfit® is an intra-vaginal device, consisting of eight pressure sensors, designed to provide visual feedback of a vaginal pressure profile. This pressure profile enables the user to discriminate between IAP and PFM pressure during PFMT [2]. Real time data is sent via Bluetooth to a custom-built mobile app. A validated 12-week PFMT programme guides the user through an exercise series that increases intensity and frequency across three months. Users are requested to complete the programme once a day, five days per week. Pressure measurement data collected by the femfit® is de-identified and uploaded to a secure online server after each session.
The primary objective is to assess the feasibility of the biofeedback provided by the femfit® to effectively teach women to contract their pelvic floor muscles correctly, leading to reduced urinary incontinence (UI) symptoms. Symptoms of UI are assessed using the validated questionnaire ICIQ-UI Short Form (ICIQ-UI SF) at 0 weeks, and on completion of 12 weeks of PFMT instruction.
The second objective is to measure the change in PFM pressure during a PFM contraction, as measured by the femfit®, and a change in PFM strength as measured digitally using the modified Oxford scale (MOS). Both assessments are completed by a pelvic floor physiotherapist at 0 weeks and 12 weeks.
Study design, materials and methods
This is a prospective interventional randomised study of women who have UI (leakage at least 3 times per week, over the last 3 months). Participants are randomised into two groups. Group 1: participants use the femfit® and their own smart phone with the femfit® mobile app to guide PFMT (intervention). Group 2: participants use their own smart phone with the same femfit® mobile app, but did not have a femfit® sensor array (control). A pelvic floor physiotherapist will complete a pelvic floor assessment for both groups at 0 weeks and 12 weeks, blinded to the group allocation. This will include using modified Oxford score (MOS) and femfit® to assess PFM function. The femfit® measures the vaginal pressure profile, including both PFM pressure and IAP. Total PFM pressure (PFMPt), relative to IAP, is calculated by subtracting IAP from the PFM pressure measured simultaneously. Participants also complete questionnaires at each assessment, to measure UI symptoms and evaluate overall study experience.
Seventy women who experience UI will be recruited (based on previous, similar research studies). Potential participants are identified through hospital waiting lists for pelvic floor physiotherapy, and through public advertising on Facebook. Inclusion criteria comprise: women over 18 years; have UI; are comfortable using an intra-vaginal device; have a smart iOS or Android device; able to communicate in English; able to give full informed consent (i.e. no neurological impairment); not pregnant or < 6 weeks postpartum; no current abnormal vaginal bleeding or infection; no previous vaginal surgery; no previous pelvic floor physiotherapy; not currently using a pessary; not have Stage 2 prolapse or greater; and BMI<35.
Results
To date, 18 women have completed the study (Table 1). For women undergoing non-surgical incontinence treatment, a reduction of 2.5 points in ICIQ-UI SF is perceived as “a little better”, 4 point reduction is perceived as “very much better” or “much better” [3]. 71 % (5/7) Group 1 participants and 45 % (5/11) in Group 2 had a reduction of at least 4 points (Figure 1). For these participants, PFMT adherence ranged from 55 % to 97 % for Group 1 and 25 % to 117 % for Group 2, with an average of 71 % and 77 % respectively.
In Group 2, two participants reported an increased ICIQ-UI SF Score (+2, +3), and one had no change. These three participants had adherence of 107 %, 87 % and 80 % respectively (adherence > 100 % indicate exercising more than 5 times per week).
Interpretation of results
On average, both study groups reported a reduction in UI symptoms. All participants in Group 1 (femfit® and app), have a reduced ICIQ-UI SF Score, while two participants in Group 2 reported an increased ICIQ-UI SF Score, and one had no change. It is interesting that these three Group 2 participants had adherence rates above average, but reported ‘worse’ symptoms. Participants were not instructed how to undertake effective PFM contraction and, as they used only the mobile app (did not receive any biofeedback), these worsening symptoms could be due to incorrect PFMT technique.
It is promising to see (on average) an increase for both the MOS and the absolute PFM pressure as measured by the femfit® in both groups. However, at this stage the study population is small (and with large standard deviations) so no statistical analysis has been performed.
Reliable tracking of adherence data for Group 1 is available due to collection of pressure data, while adherence results for Group 2 may be inaccurate. Group 2 participants may select the PFMT via the app, but may not complete the prescribed training programme. Although results are preliminary, the lower adherence in Group 1 is still achieving desirable results. Perhaps the key to success is: effective biofeedback leads to effective PFM activation, thereby promoting change in muscle function and resolution of UI.