Author's response to reviews

Transcription

1 Author's response to reviews Title:Effects of Controlled Breathing Exercises and Respiratory Muscle Training in People with Chronic Obstructive Pulmonary Disease: Results from Evaluating the Quality of Evidence in Systematic Reviews Authors: Christine R. Borge Kåre Birger Hagen Anne Marit Mengshoel Ernst Omenaas Torbjørn Moum Astrid K. Wahl Version:3Date:11 September 2014 Author's response to reviews: see over

2 Dear Editor office BMC-series Journals BioMed Central Concerning: MS: entitled "Effects of Controlled Breathing Exercises and Respiratory Muscle Training in People with Chronic Obstructive Pulmonary Disease: Results from Evaluating the Quality of Evidence in Systematic Reviews". Thank you for reviewing our manuscript once more with useful comments to the new manuscript. We have revised the manuscript in accordance with the reviewer s comments. For each comment, see our response below. To answer some of the comments more clearly, we have rearranged and rewritten some of the information in the background and the discussion. All changes have been written in red in the new document. Reviewer 1: Didier Saey 1) Comments: As highlighted by the 3 reviewers, the Inclusion in the same review of several strategies (breathing techniques and respiratory muscle training by example) with clearly different aims and mechanism of action still challenging. Response: Thank you for clarifying this important point once more. We agree with reviewer 1 and 3 that the inclusion of breathing control exercise and respiratory muscle training should be more descriptive, explaining the difference of aim and action. We have changed the previous version of the manuscript to make this point clearer. See also response to comment 2. 2 ) Comments: Also, the difference between breathing technique and BCEs still unclear. By example, P4 in inclusion and exclusion paragraph, it seems that muscle training is a breathing technique. This is not exactly true and need to be clarify Response: There is inaccuracy in the literature regarding respiratory muscle training being a breathing technique. A much referred author (R. Gosselink) has used the term breathing technique ( 2004) as an all embracing term for range of techniques such as slow and deep breathing, pursed lip breathing, relaxation therapy, body positions, inspiratory muscle training and expiratory muscle training. Gosselink (2003) also uses the term controlled breathing in combination with relaxation, pursed lip breathing, diaphragmatic breathing, and in order to improve inspiratory muscle function. Gosselink has for instance been referred to in the American Thoracic Society/European Respiratory Society Statement of Pulmonary Rehabilitation under the heading Self-management Education and co-heading Breathing Strategies 1

3 (Nici et. al. 2006), page 173. Also the Guidelines for the physiotherapy management of the adult, medical spontaneously breathing patient (Bott et. al. 2014) refers to Gosselink (2004) under the heading Breathing exercises, but makes use of separate terms of the concept inspiratory muscle training (page i10-i11). Further teaching books of respiratory problems such as Physiotherapy for Respiratory and Cardiac problems (Pryor and Prasad 2008), employ the term breathing techniques in combination with thoracic expansion exercises and inspiratory muscle training. Here there is also a reference to Gosselink (2004). Another example of different usage of terms is found in the article of von Leupoldt et. al. (2012) Behavioral Medicine Approaches to Chronic Obstructive pulmonary Diseases where they for instance use the terms Breathing Training and Respiratory muscle training under the heading Behavior Medicine treatment. Considering the diverse practice of umbrella terms it might create additional inaccuracy to introduce another concept. We have therefore chosen to only use the terms breathing control exercises and respiratory muscle training. Reviewer 2: Dina Brooks Comments: No further comments Response: Thank you for reviewing the manuscript once more. Reviewer 3: Catherine J. Hill 1a) Comments: There still, however does not appear to be a rationale for why both respiratory muscle training and controlled breathing exercises are combined in this overview and there is still a lack of clear separation as to the rationale (which is different) for each approach. The authors have added information to the background. What is the sequel of the events described in sentences 2,3 and 4? Do the authors hypothesis that weak respiratory muscles cause an increase in respiratory rate which causes hyperinflation, or does airflow limitation cause a reduced inspiratory time and shortening of respiratory muscle fibers and increase in work, leading to weakness? This is important in the rationale (and needs referencing) and also from the point of view of patient selection for respiratory muscle training do you need to determine that muscles are in fact weak before you attempt to strengthen them? It also affects the quality of studies included in the reviews do they include outcomes of muscle strength and have the correct subjects been included? Severity of airflow obstruction in COPD does not necessarily equate to muscle strength/weakness. The differences in rationale, technique and mode of action are greater than the similarities - both strategies being non-pharmacological interventions to improve breathlessness (paragraph 2, page 3) is perhaps not a strong enough argument to justify lumping them together. (Further major compulsory revision required) 2

4 Response: We agree with you that we had not appropriately clarified the rationale of including the respiratory muscle training and breathing control exercises in the previous manuscript and have now rewritten background information and discussion in the new version. Se also response to reviewer 1 comment 1 and 2. We also agree that the information about physical respiratory changes in COPD needed clarifying. This has now been changed and hopefully satisfactory. The aim of this paper was to evaluate subjective outcomes of breathlessness, other symptoms and quality of life. That s why we did not include information about the different physical rationale behind each breathing control exercise and respiratory muscle training in the previous versions. We have however seen that more information could give a more correct view of the rationale of effect, for instance regarding breathlessness. In the new version we have discussed and given more information from the systematic reviews as for this point. We have also included information and discussed the point on which patients might benefit most from practicing inspiratory muscle training. 1a) Comments: It would perhaps be helpful here to include the definition of a systematic review (rather than just a text reference) that was used by the authors to justify their inclusion of poor quality reviews. Generally, just specifying which search terms were used and which databases were searched is not considered systematic. Systemic reviews usually require a predetermined methodology which describes considerations such as the intended population, specific inclusion and exclusion criteria, interventions that will be included, acceptable comparison groups, outcomes to be considered and study design that will be considered (Discretionary revision). Response: In the new version of the manuscript, the definition of systematic reviews is included from the book Rehabilitation Research of Carter et. al. (2005). We have however, not changed our search term. We believe that too strict methodical evaluation criteria in this overview such as inclusion criteria of more than search term in data bases, could risk excluding important reviews. The AMSTAR criteria evaluate many of the important points that a systematic review should contain. For instance are research questions and inclusion criteria evaluated in point 1 of the AMSTAR criteria: Was an apriori design provided? According to table 3 in our overview, all the systematic reviews that we included fulfilled this question. Thus we believe that we have included systematic reviews according to the definition we have chosen in this overview. The Cochrane definition of systematic reviews are however stricter, but our overview aims to evaluate more than Cochrane reviews. That is the reason why we did not include this definition. After considering the content of a systematic review once more, we have decided to exclude several of the articles where the authors define their review to be either integrative review or literature review. The new manuscript now contains seven systematic reviews. Since we mostly have discussed the systematic reviews of high quality, the main point discussion of the AMSTAR criteria are still the same. 3

5 2) Comments: The authors have adequately clarified the population of the review Response: Thank you for this. 3) Comments: There are a number of breathing exercise techniques that have not been included in the review. It would perhaps be helpful for clarification of the inclusion criteria to state that the controlled breathing exercises considered for inclusion in this overview were limited to those most commonly described (refs provided in the authors response) being diaphragm breathing, yoga breathing, positioning or relaxation exercises and pursed lip breathing. (Discretionary revision) Response: We have added this information both in the background section and in the inclusion criteria. 4) Comments: The authors have not addressed their strong conclusion regarding relief of dyspnea with pursed-lip breathing considering the data presented. In the results section the authors state there were no consistent effects of pursed lip breathing, diaphragmatic breathing or yoga breathing on dyspnea or health-related QOL in relation to these data (P9, 2nd paragraph). Yet Abstract results state one high-quality SR found a significant positive effect of PLB on dyspnea, Discussion states among breathing control exercises, pursed-lip breathing had a positive effect on the reduction of dyspnea (p10 1st paragraph) and Conclusions PLB has effect on dyspnea and overall Conclusion from the overview pooled analyses showed a relief of dyspnea when pursed-lip breathing was used. (Major compulsory revision required) Response: We apologize for giving misleading information in the different sections of the manuscript. The information has been corrected in the new version (i.e. abstract, results, discussion, conclusion), and are hopefully satisfactory. 5) Comments: The authors have aimed to summarize the results and review the quality of published systematic reviews of both breathing control exercises and respiratory muscle training. Perhaps it was not the aim or intention of the overview to consider the quality of the evidence included within those systematic reviews. However, I am not sure of what interest or relevance this overview has to the reader if it only appraises the quality of the methodology of the systematic reviews and not the evidence included within those reviews (i.e. the primary studies) and the strength of conclusions Response: We agree with you that detailed information from the primary studies in the SRs may be lost in an overview. This information has been stated in limitations. However, our intention has been to give an evaluation of the actual results in the systematic reviews and give readers information about the quality of the systematic reviews. Hence, to give illuminate the strength in the literature of evidence on the effect of respiratory muscle training and breathing control exercises. 4

6 Teaching institutions, governments, patient s organizations, guidelines and books make use of systematic reviews on decision making and information. Our impression is that researchers are more critical to the information given in a review, but not all readers are aware of the correct standards of a systematic review and they may therefore read without critical thinking. As stated in the definition of systematic reviews, bias results may be the consequence if outcomes from studies are unsystematically presented and evaluated. Oslo, June 2014 On behalf of the authors, Yours sincerely, Christine R. Borge 5