Title:Continuity of GP care is associated with lower use of complementary and alternative medical providers A population-based cross-sectional survey

Transcription

1 Author's response to reviews Title:Continuity of GP care is associated with lower use of complementary and alternative medical providers A population-based cross-sectional survey Authors: Anne Helen Hansen (anne.helen.hanzen@gmail.com) Agnete E Kristoffersen (agnete.kristoffersen@uit.no) Olaug S Lian (olaug.lian@uit.no) Peder A Halvorsen (peder.halvorsen@kraftlaget.no) Version:6Date:30 September 2014 Author's response to reviews: see over

2 Dr. Anne Helen Hansen Norwegian Centre for Integrated Care and Telemedicine, University Hospital of North Norway PO Box Tromsø Norway Tel Tromsø September 29 th 2014 Dear Editor Continuity of general practitioner care is associated with lower use of complementary and alternative medical providers - a population-based cross-sectional survey With reference to our first cover letter dated May 19 th 2014 we would like to thank the editor and the reviewers for a thorough review of our manuscript. We have revised it to take account of the points raised, and feel that the paper has been improved as a result. Our responses to the editors and the reviewers concerns and suggestions are provided below. Editor s comments 1. We recommend that you copyedit the paper to improve the style of written English. If this is not possible, you may need to use a professional language editing service. The manuscript has been audited by professional language editing services. Reviewer Alice Kongsted Main concerns 1. The validity of self-reported health care utilisation. We find this concern to be highly relevant, and have mentioned it in the limitations section of our paper. However, since complementary and alternative medical (CAM) providers in general are not required to keep records in Norway, registry data are lacking. Self-reported survey data are thus probably the best source of data for studies of CAM provider use. We have added a clarifying comment about this in the methods section, and also elaborated on this in the limitations section. Please see below. 2. The interpretation of the strength of the observed association, and (...) the discussion tends to deal with the observed findings as if associations were causal. We have modified and clarified the text throughout the paper according to this concern. Please see below. Introduction 1

3 1. Continuity is assumed to be associated with quality and efficiency in delivering health care, I realize that you use the word assumed to, but is there any evidence supporting this that you could refer to? Should it be patient experienced quality and efficiency or is continuity believed to relate to measurable quality? We agree in the point raised, and a reference has been added. 2. I think a short explanation of the patient-list system would be helpful. Methods We agree with the reviewer s concern, and have added more information about the Norwegian list system in the background section. 3. Has the questions about the use of CAM providers been validated? I guess asking about visits that may have happened a year ago is prone to recall bias. Also, I wonder if all the listed CAM providers are equally socially accepted in Norway. Could it be that some people don t want to report CAM if listed with other providers that are considered more extreme? Please, add what is known about the validity of the question. Unfortunately, the question about the use of CAM providers has not been validated. Please, see also point number 1 above under the heading Main concerns. We have added a comment on this in the limitations section. The reviewer points out that all the listed CAM providers might not be equally socially accepted and we have added a comment on this point as well, linked to our previous comments about recall bias and underreporting in the limitations section. 4. Have the questions about GP duration and frequency been validated? These questions have not been validated, and we have added a comment about this in the limitations section. 5. Please, describe how the multivariable regression models were build. Were all covariates introduced at once and kept in the model or was some form of model reduction performed? We have added a comment about this in the methods section under the subheading Analyses. 6. Were all possible first order interactions tested? Yes, all interactions that could possibly be tested from the main regression model were tested for the whole sample, as well as for genders separately. Only one statistically significant interaction was found, which we reported. 7. What significance level was used? 2

4 Results P=0.05 (5%). However, in the paper we report 95% confidence intervals instead of p- values. 8. From the discussion I understand that publications regarding the representativeness of the Tromsø 6 are available. I think it would be helpful referring to that when stating the response rate. The references have been added. 9. I think it should appear from the text that 17% with short GP duration and 13% with long GP duration had visited a CAM provider. According to this suggestion the following sentence has been added: Among those with GP duration of more than 2 years, 12.5% had visited a CAM provider, whereas 17.2% with a shorter GP duration had visited a CAM provider in the previous year (Table 1). 10. The sentence Other predictors of CAM utilization were could be specified by making clear that this was in the multivariable model. I also suggest avoiding the word predictors since this implies that the association was investigated in a longitudinal design. I would prefer Other factors associated with The text has been changed as suggested, both in the abstract and in the results section. 11. It is not clear from the description of modification by gender if men or women had the strongest association (although this becomes clear in the discussion). Discussion We have added this point to the results section: However, the association between CAM use and GP frequency was modified by gender, and the association was stronger in women (interaction term GP frequency x gender, OR 0.72, CI ). 12. Please modify the statement. the probability of visiting a CAM provider was significantly lower among those with a long GP relationship compared to those with a short relationship which may be interpret as the association was strong. I think crude differences of 12% in those with a long versus 17% in those with a short relationship is a modest difference, and adjusted odds ratios around 0.8 with upper limits of 95% CI intervals above 0.9 indicate that the association may actually be weak. We have modified this statement and made changes according to this point consistently throughout the paper. Among other things, we have deleted the word significant from the abstract, and written statistically significant in the summary of the study in the discussion section. Please see also point 9 under the heading Results. 13. It says in the 2nd paragraph of the discussion Our main finding adds to the 3

5 pattern that continuity of GP care reduces the use of emergency departments, hospitalisations, and outpatient specialists [8, 9] However, it does not appear that there is evidence for a causal relation and I think the statement that continuity of GP care reduces use of other health care should be avoided. We agree, and have clarified that this is an association, not a causal relationship by rewriting the phrase: Our main finding adds to the findings that continuity of GP care is associated with reduced use of Generally it needs to be clear from the discussion that it is still unrevealed whether people seeks less care from other providers because they see the same GP continuously and that the suggestions put forward how continuity may affect CAM utilization are speculative. The observed associations could be due to unmeasured confounding. As shortly mentioned at the end of the discussion there may be other reasons than those captured by the measured covariates why people who tend not to change GP also not tend to seek much health care. It could be speculated that this relates to patients illness beliefs or coping strategies. We agree, and have put effort in clarifying this in the new version of the paper, including adding to the limitations section that our results may also be confounded by patient factors such as illness beliefs, coping strategies, and expectations of health care services. We have also chosen to introduce the word speculate into the discussion where it seems appropriate. 15. I think the discussion including the examples of unmeasured potentially relevant confounders is very focused on explanations related to the GP rather than the patient. I find it likely that there are patient characteristics like illness beliefs and expectations to health care that could affect CAM seeking and GP duration. Please see our comments on point 14 above. 16. Also, CAM utilization is presented as something mainly negative. Maybe some people are actually taken good care of by CAM providers and don t find it important to have the same GP if waiting time is long or they move to another part of the city. It has not been our intention to present CAM utilization as negative. We appreciate that the reviewer do mention this, and we have read through the paper with this aspect in mind, looking for possible changes that could be made to take account of this point. Among other things, in the fourth paragraph of the background section we now use the word interact instead of interfere for this reason. As mentioned in the paper, it seems that CAM use is additional more than alternative to GP care. 17. I think it is worth mentioning as a limitation also that the reasons for having many GP visits are unknown. Patients having many visits due to one chronic condition may differ substantially from patients who have visits related to many different complaints. 4

6 We agree that the reasons for frequent GP visits are many and unknown. However, we do not consider this a limitation regarding our study. Rather, it could be subject of another study to go more specifically into the reasons for GP visits and possible associations to CAM provider utilisation. 18. This paper is one of four papers on continuity of GP care and health care utilization. It seems to me that chiropractic care and physiotherapy was not part of any of these. If this is the last paper it is relevant explaining why since musculoskeletal complaints are among the most frequent reasons for seeing a GP. We realise that we have not been sufficiently clear about this. For clarification: this is our second paper on continuity of GP care and health care utilisation. The first study dealt with utilisation of specialist services. It is correct that use of chiropractic care and physiotherapy has not been studied by our group. At the present we do not know if such a study might be conducted in the future. Discretionary Revisions 19. I think use of subheadings in the method section would be beneficial. E.g. dividing the section into The survey, Measures of health services and Data analyses. Subheadings have been added to the methods section as suggested. 20. I am aware that the terms multivariate and multivariable are often used interchangeably. However, I think multivariable should be preferred when testing multiple predictors and one outcome. We agree, and have changed the text as suggested. Accordingly, we have used the term univariable instead of univariate. Reviewer Susan C. Slade 1. The research question has not been articulated and is not well defined. The hypothesis we hypothesise that a long lasting GP-patient relationship would be associated with reduced likelihood for using CAM providers does not match the title of continuity of care long lasting and continuity are not the same. There needs to be a definition of medium and long-term and long-lasting. Although a research aim is stated in the abstract there are no explicit primary and secondary aims stated in the manuscript. We agree in the points stated here. The term long-lasting is no longer used. We have specified the aims of the study and clarified the research question. We have also added to the limitations section that GP duration as a measure of continuity may be a subject of discussion, but argued that it might be a good proxy in the context of our study and the Norwegian list patient system. Background section 5

7 Paragraph 2 provides summary statements that are used as evidence but some are dated and there is no evidence of a systematic search and evaluation of the literature why should we believe the findings of the cited papers. Unfortunately, there is a small body of research on continuity of GP care from recent years. Our literature search refers to PubMed and Google Scholar and the terms continuity of patient care, continuity of general practitioner care, interpersonal continuity, and continuity in primary health care in combination with the CAM terms CAM complementary therapy and complementary and alternative medicine in addition to the MeSH-term complementary therapies. A search was also done for each of these terms separately. However, it should be mentioned that non-concise terms in this research area hampers a qualitatively good literature search. Thus, we have chosen not to include this information in the manuscript. Page 5, line 104 statement that is defended as an unpublished observation of AEK is unacceptable as evidence. We agree that this is not the best reference, and have explained more in the text about our estimation of the number of CAM providers in Tromsø. We have added a reference to the Register of CAM Practitioners. However, the unpublished observation it is the only available reference for our overall estimate. In the BMC Instruction for Authors it is stated that unpublished data and personal communications should not be included in the reference list, but may be included in the text and referred to as unpublished observations or personal communications giving the names of the involved researchers. We have tried our best to follow this instruction. The way in which parts of sentences are referenced is unusual and not entirely believable more comprehensive explanations are required. We have read through the manuscript with this aspect in mind, looking for possible changes that could be made to take account of this point. We hope that the reviewer and the editor will find that the changes that are made and the explanations that have been added are satisfying in meeting the concerns of the reviewer. Please also pay attention to our comments on the other points raised by the reviewer. The background does not adequately position the reason for conducting this study. Although there are no reporting guidelines that are specific to surveys the STROBE guidelines could provide a framework for the structure of this manuscript. We appreciate the reviewer s recommendation of the STROBE guidelines. We have to a greater extent structured our manuscript accordingly. Particularly, we have made efforts to better explain the reasons for performing this study. Please, see the last two paragraphs of the background section. 2. The opening sentence of the methods section seems irrelevant. We agree. The sentence has been deleted. An explanation of why a survey is the best method to answer the research question is required. 6

8 We agree. An explanation has been added. Please, see also our comments to reviewer Alice Kongsted s point number 1 under the heading Main concerns. Methods section is difficult to follow and needs a logical flow of sub-sections of, for example, eligibility criteria, participant recruitment, ethics (explanatory statement and informed consent), defence of sample size, data collection (more specifics about the survey) and data analysis. It is not clear that this work is part of the Tromso 6 study this needs to be explicitly stated and described. It seems that this paper is analysis of Tromso survey data but some of the text implies that the authors of this paper conducted the study not very clear. Consider - non-response analysis, details of strategies used to increase response rates (e.g., multiple contacts, mode of contact of potential participants), and details of measurement methods (e.g., making the instrument easily available so that readers can consider questionnaire formatting, question framing, choice of response categories, etc.). We have structured the methods section in sub-sections and rewritten the text. We have added more specific information about The Tromsø Study, and clarified our use of data from the survey. Still, there might be more details that could be presented, but we feel that it would be beyond the aims and scopes of this study to go into further details than we have done in this last version of our paper. For interested readers, the references might be helpful. What outcome measure is used for Self-rated Health what is the scale and what are the units of measure. We refer to line 153 in the first manuscript. We have rewritten the text in the new version of the paper and hope that this point is sufficiently clarified. 3. Are the data sound? In the results section provide a flow diagram into the study. The summary data appear sound but there are no raw data from which the reviewer can make calculations of OR etc. The results tables need considerable clarification for them to be easily understood by the reader the layout is confusing and units of measure are required. Unfortunately, this has not been clear enough. We have provided a flow diagram of the study population (Figure 1), and added raw data into Table 1. We have clarified the original tables with more units of measure. We have deleted the confidence intervals from Table 1 in order to make the table smaller and the layout better. 4. Does the manuscript adhere to the relevant standards for reporting and data deposition? No. See above. Please, see our responses to the reviewers concerns stated above. 5. Are the discussion and conclusions well balanced and adequately supported by the data? The Discussion is far more extensive than the research methods and results can support. There is insufficient rigour and transparency in the methods for the conclusions be fully believable and generalisable. We have rewritten the methods and the discussion sections and modified the text throughout the paper according to this point. Please, see also our responses to reviewer Alice Kongsted`s point number

9 6. Are limitations of the work clearly stated? Limitations are presented but they are not extensive and do not address the concerns of this reviewer. We have added important points set forth by the reviewers into the limitations section. Please, see also our responses above. 7. Do the authors clearly acknowledge any work upon which they are building, both published and unpublished? There is a recommendation for further research but no specific recommendations. Please, see our responses above. We have chosen to remove the sentences about further research since this point might be obvious. 8. Do the title and abstract accurately convey what has been found? Not completely. We have changed the title and the abstract according to this concern. Please, see our responses above. 9. Is the writing acceptable?the current writing style and presentation needs clarification and a more structured logical flow with sub-headings to assist the reader. Please, see our comments above and the suggested changes in the manuscript. Thank you again for your thorough review, which was most helpful when revising our paper. We hope that the revisions made will meet the reviewers concerns, and that our manuscript will be considered acceptable for publication. Kind regards Anne Helen Hansen Corresponding author Norwegian Centre for Integrated Care and Telemedicine, University Hospital of North Norway /University of Tromsø The Arctic University of Norway Norway 8