Title: PELVIC FLOOR MUSCLE TRAINING WITH BIOFEEDBACK OR FEEDBACK
FROM A PHYSIOTHERAPIST FOR URINARY AND ANAL INCONTINENCE AFTER
CHILDBIRTH - A SYSTEMATIC REVIEW
Version: 2 Date: 18 Aug 2023
Reviewer's report:
Thank you for the opportunity to read and review this manuscript. This is a review with
great potential to contribute at an academic and clinical level. This is a systematic review that
aims to examine the scientific evidence regarding the impact of PFMT with feedback, either
from a physiotherapist or biofeedback, on incontinence in women during the first six months
following vaginal delivery. The literature search was conducted in January 2023. The researchers
addressed to previous reviewers' comments satisfactorily, however some points still need to be
worked on. The authors need to decide whether to use American or British English, the text
mixes a bit of both (e.g. physiotherapist versus physical therapist; physiotherapy versus physical
therapy; randomized versus randomized). I also suggest that authors follow a pattern regarding
the use of the terms feedback and biofeedback. Some information is presented in multiple ways.
Title – the term incontinence alone can lead readers to misinterpret the content of the
review. I would suggest something like “PELVIC FLOOR MUSCLE TRAINING WITH
BIOFEEDBACK OR FEEDBACK FROM A PHYSIOTHERAPIST FOR URINARY AND
ANAL INCONTINENCE AFTER CHILDBIRTH - A SYSTEMATIC REVIEW” or simply
“PELVIC FLOOR MUSCLE TRAINING WITH BIOFEEDBACK OR FEEDBACK AFTER
CHILDBIRTH - A SYSTEMATIC REVIEW”
Abstract – To draw an intuitive connection between readers and the existing literature, I suggest
the following: to use the term “feedback” only to refer to the verbal information provided
by the physiotherapist based on vaginal/anal palpation or perineal observation and the term
“biofeedback” for the use of equipment. Therefore, the aim would become something like
“to examine the scientific evidence regarding the impact of PFMT with feedback from a
physiotherapist or biofeedback on urinary and anal incontinence in women during the first six
months following vaginal delivery.” It would be interesting to mention the comparison group.
Where was the manual search conducted? It is stated in the conclusion “compared to treatment
without feedback”, but the comparison needs to be clearer. In that sentence, it seems that the
comparison group was PFMT without feedback.
Background – This section introduces the subject and highlights the gap; however, it is a bit long.
Frist paragraph - The sentence “Anal incontinence (AI) is defined as the involuntary passage of
gas or stool (solid or liquid)” needs to be complemented by “where”. It would be interesting to
mention the reason for such a wide range of UI prevalence during postpartum. Is the prevalence
of AI after operative vaginal delivery? Please, add “during postpartum” after “recovery of
pelvic floor structures” on the last sentence. It would also be important to mention the rates of
unrecovered cases.
Second paragraph – The first sentence “UI is associated with female sexual dysfunction, both
in women of all ages and in postpartum women (10,11).”  is not adding information to the
discussion, I suggest deleting it.
Third and fourth paragraph – It is not clear which information is related to the postpartum
women or women in general. I suggest organizing the information in an order from the general
population to postpartum women. I strongly suggest avoiding using the term incontinence alone.
Fifth paragraph – It would be more appropriate to use the term “vaginal digital palpation”
instead of “manual vaginal palpation” (Frawley et al., 2021). Verbal feedback based of perineal
observation from a therapist is also described in the literature. Sixth paragraph – which
intervention PFMT + ENS with or without BF was compared in the sentence “The results showed
that PFMT and electrical stimulation with or without biofeedback were effective”?
Seventh paragraph – It is a little disconnected from the rest of the background. Both reviews
mentioned on the previous paragraph were not focusing only on feedback and/or biofeedback
and mix different interventions that could confuse the effect. That could be addressed here.
Eight Paragraph – Please, see my suggestion back in abstract. It would be important to make it
clear the comparison in the study aim once it was considered an inclusion criteria. Why was the
time frame of 6 months chosen and how was it approached? I can understand different things
from different parts of the text in relation to that time frame. I understand by reading the objective
that the treatment must had started and finished at the end of 6 months since delivery. However,
the exclusion criteria are only for starting treatment outside that time frame. If the first is the
right interpretation, then I am afraid that Ahlund et al (2013) should be excluded from the review
(Starting date at 10 to 16 weeks postpartum + 6 months of intervention).
Methods –The first paragraph could be summarized in something like “A systematic literature
search was carried out based on previously established selection criteria to achieve the purpose
of this systematic review (see Table 1). The Cochrane handbook (34) and PRISMA guidelines
(35) were followed.”
Eligibility criteria - Why was it chosen to only include studies which intervention was provided
by a physiotherapist? This adds a potential bias to the interpretation of findings as other health
professionals are responsible for assisting postpartum woman in some countries. It would be
important to highlight the reasoning for this choice as well as discuss the implication for
Overall completeness and applicability of evidence. The criteria for comparison group still
not clear enough. Do the authors mean active treatments regardless of supervision when they
mention other treatments? Could feedback or biofeedback be compared to group exercises?
If we considering the expression “self-assessment questionnaires”, would studies in which the
researcher applied the questionnaires be excluded? I have a similar concern about the inclusion
criteria “literature must be in English” as the criteria “from a physiotherapist”. This should be
address in the discussion as a potential source of selection bias. I would also encourage the
authors to perform an additional search without the exclusion criteria of studies published earlier
than 2012 or discuss this as a limitation to the completeness of evidence. The oldest study
included on the Cochrane review (Herdershee et al., 2011) with the same topic for a different
population was published in 1983.
Literature search – Was the search adjusted to each database? It seems not considering the
information presents in “additional file 1”. If the same search strategy was used in all databases,
the additional file 1 could present only one search strategy as the number of hits per search block
is being presented in table 2. The search strategy is mixing American and British English. It
would be relevant to address both on the strategy.
Screening – Was any review management software used during screening process? Was manual
search also performed by two independent reviewers? Assessment of clinical relevance – I
suggest adding more details on what the authors considered to classify an interventions and
treatment settings described as well described enough that the readers could provide the same
for their patients. I suggest using CERT-PFMT as theoretical framework (Slade et al., 2021).
Additional information – I strongly recommend adding another section into methods presenting
the differences between the PROSPERO-registered protocol and discussing why those changes
were necessary. I could identify difference in population (tears from childbirth degree 2-3).
Results – I suggest organizing the first paragraph as follows: total number of records, screening
process and only then the number of included studies.
Characteristics of included studies – It would be important to have a more detailed description
on participants and settings (e.g. what was the age range? mean number of pregnancies?
range of time in postpartum in which women were recruited? In which countries were
conducted?). Do the authors really mean that “The remaining studies included women with self-
reported incontinence”? if so, that would go against the inclusion criteria because self-reported
incontinence and self-assessed questionnaires are two different things. The second paragraph
would be easier to understand if starting with something like “Of the 8 studies included, four
studies reported using biofeedback devices while four reported participants receiving feedback
from….”. The authors wrote “In all intervention groups, participants received a home exercise
program with PFMT.” but it is not clear if any of them were using biofeedback device at home.
The authors mentioned the use of e different biofeedback devices. Was this difference relates
to the signal or only the manufacture?
Table 5 - Why was table 5 presented as a separate document? Please, follow a pattern. I strongly
suggest the authors to present the intervention and control group information in items following
CERT-PFMT. According to what is presented, it seems there are 4 studies on PFMT + feedback,
2 studies on PFMT + biofeedback and 2 studies on PFMT + feedback + biofeedback.  It is
not clear which measurements and variability data are being presented in results column. Is it
possible to present or back calculate most of the data in one measurement and one variability?
This could allow data pool. The data is being presented in a way that looks like it could be
possible to pool data as SMD for UI (44, 46, 48) and AI (43,44,46).
Results of included studies – In the sentence “Three of eight studies reported a significant
difference between the groups, with participants in the intervention groups showing reduced
incontinence symptoms”, to which incontinence are the authors referring to? I suggest
organizing the presentation of the results considering the lower to the higher time frame during
postpartum.
Methodological quality – I suggest the following table organization for additional file
3: 1. Eligibility criteria; 2. Random sequence generation; 3. Allocation concealment; 4.
Homogeneous baseline data; 5. Blinding of all participants; 6. Blinding of therapists who
administered the therapy; 7. Blinding of all assessors; 8. Attrition rate higher than 85%; 9. Was
analysis by intention to treat?; 10.  Between-group statistical comparisons are reported for at
least one key outcome; 11. Both point measures and measures of variability for at least one key
outcome were provided.
Probative value – The text is a little messy and repeat the same structure of sentence over
and over.  I would suggest something like “One of the studies was considered to have a high
probative value (46). Two studies were considered to have a medium level of evidence (42,47),
and five studies had a low level of evidence (41,43–45,48). Two study was considered to have
high methodological quality, but a medium level of evidence due to number of dropouts (47)
or because the groups were not equal at baseline (42). Four studies were considered to have
medium methodological quality, but low evidentiary value (41,43–45) due to not reporting
or not homogeneous baseline values (44,45), problem with the power calculation (41,45)
and an excessive number of dropouts (41,43). In addition, one study considered having low
methodological quality was also classified as low level of evidence due to not perform a power
calculation, lack of random allocation and high number dropouts (48) (See Table 6).”
Clinical relevance – See my comment back in methods. I would also suggest adding some
kind of legend to what the numbers mean (1. Detailed description of participants; 2. Detailed
description of interventions; 3. Use and report of clinically relevant outcome measures; 4.
Clinically important effect size; 5. Benefits overcome potential harms)
Grading of evidence – Most of the data presented here has been presented previously. The
authors mentioned “There are not enough studies with a high level of evidence, and no study was
assessed as clinically relevant. In addition, the results in the included studies are contradictory;
the scientific basis is therefore considered to be insufficient.” However, that’s not in accordance
with table 4 which states that it would be considered moderately strong scientific evidence when
“One study with a high level of evidence plus at least two with a medium level of evidence.”.
The researchers have one study with a high level of evidence (46), two studies with medium
level of evidence (42,47) and five studies with low level of evidence (41, 43-45,48). Please,
make this decision process clear.
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