Editor in chief

International Urogynecology Journal Oslo, December 7th 2014

Revision of manuscript number: IUJO-D-14-00435.

Thank you very much for the thorough and constructive revision of our manuscript IUJO-D-14-00435 entitled PELVIC FLOOR MUSCLE FUNCTION IN WOMEN WITH PROVOKED VESTIBULODYNIA AND ASYMPTOMATIC CONTROLS. We have tried our best to answer to the reviewers’ comments and questions.

The Authors answers toReviewers' comments:

Reviewer #1: This manuscript describes a study of 70 women (half with and half without PVD) to assess resting pressure, pelvic floor muscle strength and EMG studies. I have a few comments / questions:

  1. The authors incorrectly described their study design as a case-control. While they do have a group of cases and a group of controls, they did not perform a true case-control study. The controls were not selected at random from the larger group of subjects at risk who did not develop PVD.
    Reply: There are obviously different definitions of case control studies. Altman et al. describes case-control study (p.93) to be a group of subjects with the condition of interest compared to an unaffected group.Case control studies are observational. According to Altman a random selection is not required and the control can be matched as was the case here. We have inserted the reference to Altman
  1. Although the authors based their sample size on a power calculation, the assumptions they made to do so are suspect. This may explain their seemingly contradictory findings. Although the most appropriate study on which to base the power calculation showed a difference of 2.3cm H2O, they chose a clinically meaningful difference of 6.6. They did not explain how they could at the same time base a power calculation on a prior study and then not use the numbers from that prior study. It seems as though they set themselves up for a type II error when doing so
    Reply: When planning this study, there were no vaginal pressure data from patients with provoked vestibulodyniaavailable. Clinical experience from working with pelvic floor examination of women with pain (PVD) made us assumethat vaginal pressure at rest is higher among women with PVDthan for urinary incontinent women. We therefore used the difference in cm H2O (6.6) that had been foundin strength between urinary incontinent and continent women. This is further discussed in the discussion section.
  1. Page 6: - The authors state that their Q-tip device had not been tested for inter / intra rater reliability, but they then attempt to make the case that they did in fact perform an adequate assessment of same. Further justification is required.
    Reply: Weagree in this comment and have changed the sentences to: «The instrument has not yet been tested for intra- and inter-rater reliability, but repetitive testing with different loads in the same women showed reproducible results except for values below 3 grams and applied forces of more than 500 grams. The device was tested in 20 PVD patients, it was well tolerated, and the method was found to be easy to use.
  1. The authors should attempt to make the clinical significance of their findings more evident. How might their findings help clinicians or researchers in the future?
    Reply:Since the present design cannot rule out causality we hypothesize thatreduced muscular endurance may be dueto elevated resting pressure.Hence reduction of resting pressure may be important before starting PFMT strength or endurance training.However, this theory needs to be tested in a RCT.
  1. The last sentence in the manuscript is worded too strongly. An argument could be made that the authors' finding, instead, call into question their own methods for measuring the outcome measures.

Reply: The last sentence is deleted.

Reviewer # 2: This is a prospective comparative study to evaluate pain and pelvic floor muscle function in women with and without vestibulodynia.I have a few comments:

  1. This is a well written manuscript. It is a bit wordy which makes some parts difficult to follow, especially with so many acronyms. May want to consider rewording some parts for better readability and to decrease the length.

Reply: The discussion has been restructured, we have tried our best to reduce acronyms and a list of abbreviations has been added before the introduction.

  1. This is actually a prospective cohort and not a case-control study design.
    Reply: Altman et al. describes case-control study (p.93) to be a group of subjects with the condition of interest compared to an unaffected group. In the discussion part we added the sentence “In this study we matched the group of cases with the group of controls, and the data is collectedat one time point.”
  1. Can you please comment on how this would change or assist in the management of these patients?
    Reply: Since the present design cannot rule out causality,we hypothesize that reduced muscular endurance may be due to elevated resting pressure.

Hence reduction of resting pressure may be important before starting PFMT strength or endurance training. However, this theory needs to be tested in a RCT.

Reviewer #3: PELVIC FLOOR MUSCLE FUNCTION IN WOMEN WITH PROVOKED VESTIBULODYNIA AND ASYMPTOMATIC CONTROLS

  1. The correct term is "masking" not "blinding". Please comment if the screen was an adequate method by which to mask the observer. Did women flinch more in the affected than the non-affected group. Did the authors check to make sure that the observer could not determine which group women belonged?

Reply: Blinding has been changed to “masked” throughout the article.The physiotherapists assessing the patients had long experience in assessing pain patients and did this in the same way for all participants. As pain may lead to a withdrawal reflex, this may have been observable for the physiotherapist performing the test. However, pain response can occur in all participants, the physical therapists were experienced in handling PVD and other pelvic pain patients and used very gentle techniques when performing the q-tip test and inserting the devices.

  1. Many of the IUJ readers may not be familiar with all the measurements performed in this study - ie sEMG, pressure with the Q tip etc. The paper would benefit from an explanation of what each was measuring - sensory, nerve conduction, force, etc

Reply: We have added a list of abbreviationsbefore the introduction.

  1. Please define what the Crook lying position is. I am unfamiliar with it.

Reply: Wehave given an explanation in brackets: All measurements were done in supine crook-lying position (patient is lying on her back-with bentknees and feet on the bench).

  1. Why were only nulliparous patients included?

Reply: We wanted to include a homogenous study sample, not including women who could have suffered birth injuries and other birth related conditions that may cause pain.

Please also further explain why would with candida were excluded and how this was determined

Reply: Candida is one factor hypothesized to cause vulvar pain which can be difficult to differentiate from PVD. We added the sentence: “All referred patients had a test (microscopy directly or cultivation) for candida and participants with positive test were excluded.”

  1. How can you reconcile higher VRP but no increase in sEMG? This should be addressed in the first paragraph of the discussion.

Reply:We agree and have added discussion on this in the first paragraph, page 12

  1. "However, the responsiveness, reliability and validity of vaginal palpation for measurement of activation of the PFM have been discussed" What do you mean by "discussed"? Do you mean to say challenged

Reply:We have changed discussed to challenged

  1. In general the discussion portion of this paper is not well organized and needs extensive revision. In addition the discussion seems somewhat repetitive and could be shortened

Reply:The discussion has been restructured.

  1. Line 277: "There is a need for further studies to investigate the relationship between PFM function and PVD, and randomized controlled trials to evaluate the effect of different PFM treatment strategies for PVD." This statement does not add to the manuscript and should be deleted.

Reply: The sentence is deleted.

  1. The many abbreviations used in the paper make it confusing to follow. I would suggest spelling out some of them throughout the manuscript

Reply:We have spelled out some of the former abbreviationsand added a list of abbreviations in the beginning of the manuscript.

  1. There should be a more robust discussion of the weaknesses of this study. The authors clearly did not find what the thought they would, and they need to more fully explore whether or not these findings were due to some weaknesses of the study.

Reply: We have restructured the discussion part, and tried to point out weaknesses more clearly.

  1. I think that it would be helpful to state clearly at the beginning of the article what the anticipated findings were in this study.

Reply: We added the sentence “We hypothesized that vaginal resting pressure and resting surface EMGwould be higher and PFM strength and endurance lower in women with PVD compared to healthy controls.”

We hope our changes are satisfactory and that the manuscript is acceptable for publication in International Urogynecology Journal. We are happy to answer any further comments and questions.

Yours sincerely

Ingrid Næss, physiotherapist, MSc.

Kari Bø, professor, Phd