Hypothesis / aims of study
Evidence from recent clinical trials, including the Group Rehabilitation Or IndividUal Physiotherapy trial (GROUP trial), [1] suggests that group-based physiotherapy is not inferior to individual physiotherapy for reducing urinary incontinence (UI) episodes in older women with stress and mixed UI, making pelvic floor muscle (PFM) training more accessible and lessening the burden of UI on the health care system.
It is unclear, however, whether changes in pelvic floor morphometry and PFM function previously reported for the current standard of care (individual physiotherapy),[2] are comparable to a group-based physiotherapy approach. Furthermore, it is not known if both interventions result in similar self-perceived efficacy by women in performing PFM exercises and preventing urinary leakage. In this secondary analysis, we aim to investigate the morphometrical, functional and related self-efficacy effects of these two physiotherapy approaches (individual and group-based) to treat UI in older women.
Study design, materials and methods
The GROUP trial (ClinicalTrials.gov, number NCT02039830) [1] is an assessor-blind, randomized, multi-centre, non-inferiority trial comparing individual versus group-based physiotherapy with respect to the average percentage reduction in UI episodes, one-year post-randomization. The study protocol was approved by the research ethics board at each recruitment site and each volunteer provided written consent prior to participation.
Eligible participants were women age 60 and over, who reported at least three episodes of stress or mixed UI episodes per week during the preceding three months. Details on the participants’ inclusion/exclusion criteria are provided in the trial protocol.[3]
Pelvic floor morphometry, PFM function and self-efficacy data were acquired at baseline, immediately post-treatment and at one-year follow-up by an outcome assessor blinded to the participants’ intervention allocation.
Pelvic floor morphometry was obtained from transperineal ultrasound (US) volumes using either a Siemens Acuson Antares system with a 3–5 MHz curvilinear 3D/4D probe or a GE Voluson Expert system with a 2–6 MHz curvilinear 3D/4D probe, depending on equipment availability at each study centre.
PFM function was assessed using the Montreal dynamometer, consisting of two parallel aluminium branches fixed to a base, allowing for measurements in variable vaginal apertures. The lower branch has two strain gauges mounted in a differential arrangement.
Participants’ perceptions of self-efficacy in performing PFM exercises was assessed using the Broome Pelvic Muscle Self-Efficacy Scale (Part A), a 14-item questionnaire with scores ranging from 0-100.
Pelvic floor morphometrical and functional parameters in addition to perceived self-efficacy scores were compared using mixed-effects models for repeated-measures between intervention arms and over time (2 intervention arms, 3 time-points), in order to minimize the effects of missing data. The outcome was a function of the intervention arm, time-points and their interaction.
Results
A total of 362 participants were randomized to either individual (184) or group-based physiotherapy (178), of which 337 (93%) completed the intervention and 319 (88%) completed the one-year follow-up assessment. The mean age of the participants was 67.9 years old (SD 5.8). Three hundred (82.9%) had symptoms of mixed UI, and 62 (17.1%) of stress UI. Mean duration of UI symptoms was 9.7 (SD 9.8) years. Mean leakage episodes per week was 14.7 (SD 14.7).
Figures 1 and 2 summarize results for pelvic floor morphometry and PFM function. No differences were found between intervention arms (individual versus group-based physiotherapy) in most of the pelvic floor morphometric and PFM functional parameters for all time-points. However, positive post-treatment changes in pelvic floor morphometry and PFM function were observed in both groups and were maintained at the one-year follow-up.
For pelvic floor morphometry, changes over time were not observed during rest or PFM maximum contraction task but were observed during cough task. Participants in each intervention arm presented less caudal movement of the PFMs and a smaller opening of the levator hiatus while coughing, both at post-treatment and at the one-year follow-up.
For PFM function, both interventions resulted in a stronger, faster, more coordinated and more endurant PFM contractions. Both at post-treatment and at the one-year follow-up, participants presented higher forces on the maximal contraction task; a higher number of valid rapid contractions with faster contraction and relaxation speeds on the rapid contractions task; a higher area under the curve on a sustained contraction task, and higher peak and valley forces on the triple cough task. Of interest, PFM contractions were stronger and better maintained between each cough burst.
For perceived self-efficacy, both interventions resulted in significantly higher scores after treatment and in the long-term (P<0.001), with no differences found between intervention arms or between post treatment and one-year follow-up; overall, high self-efficacy was perceived by 48 (14%) of the 334 participants at baseline, 307 (92%) of the 334 participants post-intervention and 284 (90%) of the 315 participants at the one-year follow-up.
Interpretation of results
Our results show that aging women benefit significantly and equally from either individual or group PFM physiotherapy. In both intervention arms, participants presented important post-treatment gains on pelvic floor morphometry while coughing and on PFM function during rapid, maximal and sustained contractions, and while performing triple coughs. More importantly, gains were maintained in the long term. Finally, both intervention arms reported better self-efficacy in performing PFM exercises both immediately after treatment and in long term.