PEER REVIEW HISTORY ARTICLE DETAILS TITLE (PROVISIONAL) AUTHORS

Transcription

1 PEER REVIEW HISTORY BMJ Open publishes all reviews undertaken for accepted manuscripts. Reviewers are asked to complete a checklist review form ( and are provided with free text boxes to elaborate on their assessment. These free text comments are reproduced below. TITLE (PROVISIONAL) AUTHORS REVIEWER REVIEW RETURNED GENERAL COMMENTS ARTICLE DETAILS Suicide bereavement: Piloting a longitudinal study in Australia Kolves, Kairi; De Leo, Diego VERSION 1 REVIEW Karl Andriessen School of Psychiatry, University of New South Wales, Australia 21-Sep-2017 The paper presents first results of a pilot study of a promising longitudinal study on suicide bereavement in Australia. The strengths of the study include its longitudinal perspective, the use of a reliable instrument, and a non-convenience sample. There are; however, a few points that need clarification. In the Introduction (p. 4), authors stated that previous studies beared several limitations including uncontrolled confounding variables. How dealt the current study with this issue? The study compared suicide deaths with sudden deaths. Authors stated that comparing suicide deaths with natural deaths may introduce a bias. I disagree with that. Computing the scores of suicide deaths and sudden deaths vs natural deaths would provide an interesting point of comparison. In addition, it may help shed light on the issue whether suicide bereavement is more severe than bereavement after other causes of death. I think this should be mentioned in the limitations, and if possible, included in the full study. Recruitment was based on the Queensland Suicide Register, and through the Coroner office. I understand this was not a convenience sample. However, does the QSR Coroner recruitment entail any limitations? If so, please clarify. Also related to the Method of the study, it is said (top of page 7) that the interview included validated psychological scales/questionnaires. This sentence implies that more than one instrument has been used, which makes sense. Please clarify which other scales have been used. The study was limited to a 24-month post-death follow-up. Was this timeframe sufficient to capture the course of the grief? Or would you need, or recommend another (longer?) timeframe. Only few studies have been able to conduct a 5- or 10-year follow-up. What are your findings on this point, and the implications for the full study?

2 REVIEWER REVIEW RETURNED GENERAL COMMENTS Finally, in the Introduction authors refer to an older study by Berman regarding estimating the population of suicide survivors. FYI: Recently a meta-analysis was published on this topic. I hope these comments may help in improving the manuscript, and I wish you good luck. Alexandra Pitman UCL UK 09-Oct-2017 This would be an important study to conduct, given the lack of longitudinal studies and the tendency to recruit people already in treatment. However is gives too much detail on the findings in relation to the validated measures used, rather than on the feasibility aspects it is supposed to measure. It therefore ends without conveying whether or not it would be feasible to conduct the largerscale study. Not enough detail is given in presenting quantitative and qualitative information on ease of recruitment, retention in the study, and acceptability of the outcome measures used. Introduction The opening paragraph should give a sense of how many people are exposed to suicide Eg WHO estimate of 10 Berman s 2011 estimate of 60 The most concerning effects of suicide bereavement are not mentioned Eg Risk of suicide Agerbo 2005; Erlangsen et al 2017 This needs emphasising to justify why a study of this kind is justified. Too much space is given to a discussion over the difference between a pilot and feasibility study this is outside the remit of this study, which should merely state its aims, and perhaps summarise the above in a sentence. Limitations: The following is not technically a limitation of a pilot study as it is never intended to achieve these ends: The pilot study is limited by the small sample size and inability to adjust for confounding factors. Method The sampling method is strong, and sets it apart from other studies recruiting from helpseeking samples. Where you justify/explain the choice of control group, further detail is needed to explain what is the bias referred to as would avoid potential bias when compared to natural deaths. The measure used for the primary outcome is validated and the choice of control groups is appropriate. However, it is incorrect to state that the primary outcome measure was bereavement, using the Grief Experience Questionnaire (GEQ) as this measures total grief score and a number of sub-scale scores. It is also not necessarily true that certain sub-scales are unique to suicide bereavement.

3 REVIEWER REVIEW RETURNED GENERAL COMMENTS Some results (sample characteristics) are presented under the method, when this section should present a statistical analysis plan but not results. Results Feasibility measures: Data for response need more detail eg how many did not have any contactable next of kin? Under the Results it states that The questionnaire design was considered as adequate need to explain whose view this was and whether feedback was obtained from participants or whether this was the researchers view Did you adjust for multiple testing? Do you have a specific hypothesis about any differences on subscales? Discussion You mention that response rates were not ideal but this is one of the key issues to explore in a study of this kind, and this is a key limitation of this study. A lot of detail is given over to discussing quantitative findings, but the point of this pilot study is to look at recruitment, retention, etc ( Results of our pilot study suggest that significantly higher levels of rejection, unique reactions, responsibility and total grief ) For the same reason it seems inappropriate to explore the findings of the study in the context of other studies, because they are likely to have been studies intended to test a hypothesis about GEQ scores etc, but this study was to test the feasibility of running a larger study. Some of the syntax needs revision, eg: This pilot study is a prospective longitudinal study which enables to analyse changes and differences in the suicide and sudden death bereavement over time. Rationale to include sudden deaths as comparison/control group included since arousal of symptoms Bereaving a death that occurred Ms Ailbhe Spillane National Suicide Research Foundation and the School of Public Health, University College Cork, Ireland 13-Oct-2017 Overall, this is a really interesting paper investigating a neglected public health concern. However, there are a number of major issues that need to be addressed: - Did the sample comprise consecutive cases from the Queensland Register or were they a selective sample? - Please provide details as to why confounding factors could not be controlled for - Please provide a detailed flowchart of the recruitment process. This needs to be included for every stage of the study. Include the recruitment process for the suicide-bereaved and sudden death bereaved.

4 Give refusals and withdrawals at each stage and reasons for refusal and withdrawal - The discussion section needs to be revised. What are the implications of the study findings? Please provide a comprehensive paragraph outlining the strengths and limitations of the study. Please also provide a conclusion paragraph Additional comments: In the abstract and results you refer to linear mixed-methods modelling should this be linear mixed modelling? Abstract Line of the abstract need to be made clearer. Reactions is missing after somatic in this sentence. Line 44 of the abstract: replace fitness with appropriateness Strengths and limitations (directly after abstract) Suggest rephrasing first sentence of the strengths and limitations bullet points page 2, line 55 to: This pilot study is a prospective study which allows the opportunity to longitudinally examine any differences in grief reactions for those bereaved by suicide compared to those bereaved by sudden death I also suggest that you emphasise how this study fills a significant gap in the literature in this point too Page 3, line 3: Suggest rephrasing this sentence to: The control group was recruited from information obtained via police forms Since you mentioned how you recruited the control group, you should mention that the suicide-bereaved were identified via the Queensland register. Also, did they represent consecutive cases of suicide or was it a random sample of people on the register? State whichever it is here. Page 3, line 8: When you mention that you couldn t adjust for any confounding factors, it would be helpful if you gave two examples of some of the most important factors that you cannot control for. This will be important for the reader. Please state the authors were unable to control for confounding factors. Introduction Page 4, line 7: Suggest rephrasing people left behind to people intimately affected by suicide as you are focussing on immediate family members. I would also remove (referred to as suicide survivors in the US) as this terminology can be confusing and is rarely used outside of the US. Suggest changing this sentence to: Estimating the number of people intimately affected by a suicide is a challenging task as affects appear to differ according to quality and characteristics of the relationship with the deceased and also the age of the deceased. Page 4, line 24: You mention people experiencing suicide often experience adverse physical, emotional and social outcomes. Include references at the end of this sentence and expand on this point further. Some useful references include; Bolton et al (2013), De Groot et al (2006), Pitman et al (2016), Pitman et al (2017)

5 Page 4, line 27: Remove have found to and feelings of from the sentence Page 4, line 31: Change people bereaved by suicide show high levels to people bereaved by suicide have high levels Page 4, line 36: Remove (i.e., do not remain constant); however, only a. Replace over long period of time to longitudinally Page 4, line 53: Change Research literature indicates to Research indicates a lack of consensus regarding the definition and scope of a pilot study. Page 4 line 58: Change synonymous of feasibility study to synonymous with a feasibility study Page 4, line 58: Change Leon et al write that to Leon et al defines the purpose of conducting a pilot study is to examine the feasibility of an approach that is intended to be ultimately used in a larger-scale study. Page 5 line 12-22: This sentence is too long; break this up into two sentences Page 5, line 27: You mention close relatives and in your methods you mention the inclusion criteria was immediate family members; keep the terminology consistent, use one or the other Methods Include the following headings in your methods section: study design, sample and recruitment, measures, statistical analysis Use the STROBE statement as a guideline for reporting the study using a reporting guideline is required by the journal Page 5, line 36: I m not convinced Figure 1 is required. Suggest that you describe the study thoroughly under study design and remove the diagram Describe the setting of the study where did the interviews take place, how were participants selected and how did you follow-up participants? Page 5, line 48-55: Change Rationale to include sudden deaths to People bereaved by sudden deaths were included as the control group to determine any similarities or differences in grief reactions to people bereaved by suicide Page 5, line 55: Change Under sudden deaths to Sudden deaths comprised accidents and sudden natural death mainly caused by cardiovascular conditions, where death occurred within hours of the development of symptoms. Page 6, line 15: Change Inclusion criteria of study participants who entered the pilot: to Inclusion criteria for this pilot study were: Page 6, line 27: Change Bereaved a to Bereaved by a

6 Page 6, line 46-50: You describe in this paragraph that the sudden death group were recruited via State Coroners but in the strengths and limitations directly after the abstract you describe they were identified via police forms. Please revise Page 7, line 1: Rephrase this sentence as it is unclear Page 7, line 7: You mention that the primary outcome measure was bereavement, using the Grief Experience Questionnaire (GEQ). Change this to the primary outcome measure was grief reactions, as measured by the Grief Experience Questionnaire (GEQ) Results Page 9, line 12: Crombach s Alpha s should read Cronbach s Alpha s Page 9, line 15-27: Give score for search for explanation, unique reactions etc. in brackets? In terms of your t-test, give more details on these results: was there a significant difference between the two groups, and if so, for what variables? Give the respective p-values. Refer to my previous point about linear mixed-methods modelling should this read Linear mixed-modelling? If not, please give supporting references for this statistical technique Discussion The first paragraph needs to summarise the key findings of this study and provide commentary on how this is similar or different to other studies. Give this first paragraph the heading Principal findings. Suggest changing first sentence of discussion to: Overall, there is a paucity of studies comparing outcomes following suicide bereavement to other causes of death, with some notable exceptions (provide references). Suggest changing the following sentence to: Furthermore, a very limited number of studies analysed whether outcomes following suicide bereavement changed over time. Give references for this statement. In the second paragraph of your discussion you discuss the response rate of the study state what this is here and state the response rates of a selection of studies utilising the psychological autopsy method so the reader can see how this studies compares to others. Page 10, line 53: You state However, those studies did not establish the continuing presence of this difference over time Do you mean here that these studies were not longitudinal in nature? Page 11, line 10-17: A significant decline in the total grief score this sentence is too long, break up into two sentences. Generally in this paragraph, it needs to be clearly stated whether any increases or decreases were seen across the two groups or just in the suicide or sudden death group. For example, it was stated However, there was a decline between 12 and 30 months was this across the suicide or sudden death group?

7 The paragraph starting with The results of this pilot study are obviously limited by should be given the heading Strengths and Limitations Provide a few on the strengths of the study before you discuss the limitations of the study Change The results of this pilot study are obviously limited by to This study has a number of limitations. Firstly the sample size is small but was considered adequate for a pilot study. Will confounding factors be adjusted for in the main study? State either way as a strength or a limitation depending on whether any factors will be adjusted for. Include a concluding paragraph and label it as Conclusion Further linguistic polishing of the text is required throughout the document Recommendation: Major revision VERSION 1 AUTHOR RESPONSE Reviewer: 1 Reviewer Name: Karl Andriessen Institution and Country: School of Psychiatry, University of New South Wales, Australia Please state any competing interests: None declared Comment: The paper presents first results of a pilot study of a promising longitudinal study on suicide bereavement in Australia. The strengths of the study include its longitudinal perspective, the use of a reliable instrument, and a non-convenience sample. There are; however, a few points that need clarification. Response: Thank you In the Introduction (p. 4), authors stated that previous studies beared several limitations including uncontrolled confounding variables. How dealt the current study with this issue? Response: Sample size in the pilot study is too small to control for confounding factors. We have added to the limitation section clarification that it would be feasible in a full-scale study. Comment: The study compared suicide deaths with sudden deaths. Authors stated that comparing suicide deaths with natural deaths may introduce a bias. I disagree with that. Computing the scores of suicide deaths and sudden deaths vs natural deaths would provide an interesting point of comparison. In addition, it may help shed light on the issue whether suicide bereavement is more severe than bereavement after other causes of death. I think this should be mentioned in the limitations, and if possible, included in the full study. Response: We have removed the statement that it will be biased. Considering that some studies have indicated that due to the result of the rabidity there suicide and sudden death bereavement might be more similar in some aspects and the loss of loved one to natural causes may give some degree of psychological preparedness - anticipatory mourning (Jordan & McIntosh, 2011; p.33). In light of that we were focussing on sudden deaths as a comparison group. We do agree that it would add value to have natural causes as a control/comparison group. Nevertheless, there is also a practical reason natural causes of deaths are not reportable deaths by Australian coroners, therefore it would not be feasible to recruit into that group through the coroners office, added to the Strength and weaknesses section.

8 Jordan JR & McIntosh JL (2011) Is suicide bereavement different? A framework for rethinking the question. In Jordan JR & McIntosh JL (eds) Grief after suicide. New York, London: Routledge; pp Comment: Recruitment was based on the Queensland Suicide Register, and through the Coroner office. I understand this was not a convenience sample. However, does the QSR Coroner recruitment entail any limitations? If so, please clarify. Response: That is correct, it was not a convenience sample. Limitation would be that we cannot recruit people bereaved by natural causes (as mentioned in previous response). Comment: Also related to the Method of the study, it is said (top of page 7) that the interview included validated psychological scales/questionnaires. This sentence implies that more than one instrument has been used, which makes sense. Please clarify which other scales have been used. Response: Accepted, as we said the primary measure presented in the frames of this pilot study was GEQ. However, list of other scales has been added. Comment: The study was limited to a 24-month post-death follow-up. Was this timeframe sufficient to capture the course of the grief? Or would you need, or recommend another (longer?) timeframe. Only few studies have been able to conduct a 5- or 10-year follow-up. What are your findings on this point, and the implications for the full study? Response: We agree that extending the study could add value and we have added relevant comment to the discussion (under Strength and weaknesses). Comment: Finally, in the Introduction authors refer to an older study by Berman regarding estimating the population of suicide survivors. FYI: Recently a meta-analysis was published on this topic. Response: The meta-analysis has been added and cited. I hope these comments may help in improving the manuscript, and I wish you good luck. Reviewer: 2 Reviewer Name: Alexandra Pitman Institution and Country: UCL, UK Please state any competing interests: none declared This would be an important study to conduct, given the lack of longitudinal studies and the tendency to recruit people already in treatment. However is gives too much detail on the findings in relation to the validated measures used, rather than on the feasibility aspects it is supposed to measure. It therefore ends without conveying whether or not it would be feasible to conduct the larger-scale study. Not enough detail is given in presenting quantitative and qualitative information on ease of recruitment, retention in the study, and acceptability of the outcome measures used. Introduction The opening paragraph should give a sense of how many people are exposed to suicide Eg WHO estimate of 10 Berman s 2011 estimate of 60 Response: Accepted, we added information from the new meta-analysis as per reviewer 1 comment Comment: The most concerning effects of suicide bereavement are not mentioned Eg Risk of suicide Agerbo 2005; Erlangsen et al 2017 This needs emphasising to justify why a study of this kind is justified. Response: We have added a sentence that registry based studies have identifying mental health disorders, suicide attempts suicide mortality as an outcome.

9 Comment: Too much space is given to a discussion over the difference between a pilot and feasibility study this is outside the remit of this study, which should merely state its aims, and perhaps summarise the above in a sentence. Response: Accepted, we have summarised it into one sentence. Limitations: The following is not technically a limitation of a pilot study as it is never intended to achieve these ends: The pilot study is limited by the small sample size and inability to adjust for confounding factors. Response: Thank you, we agree. Method The sampling method is strong, and sets it apart from other studies recruiting from helpseeking samples. Where you justify/explain the choice of control group, further detail is needed to explain what is the bias referred to as would avoid potential bias when compared to natural deaths. Response: Accepted, sentence has been changed and will also align with reviewer 1 comment. Comment: The measure used for the primary outcome is validated and the choice of control groups is appropriate. However, it is incorrect to state that the primary outcome measure was bereavement, using the Grief Experience Questionnaire (GEQ) as this measures total grief score and a number of sub-scale scores. Response: Accepted, it has been further clarified that with its subscales. The primary outcome measure was still grief as measured with GEQ. As per authors of the scale The GEQ was designed as primary instrument in a study comparing bereavement experience in suicide survivors with those of natural death and accidental-death survivors. (Barrrett & Scott, 1989, p.202) Comment: It is also not necessarily true that certain sub-scales are unique to suicide bereavement. Response: This point comes from the authors who developed the scale. The GEQ measures two general types of grief reactions: those expected in any bereavement and those specific to suicide bereavement. (Barrrett & Scott, 1989, p.202) Comment: Some results (sample characteristics) are presented under the method, when this section should present a statistical analysis plan but not results. Response: Accepted, text moved to the results section Results Feasibility measures: Data for response need more detail eg how many did not have any contactable next of kin? Response: All police forms have a contact person. They may not necessarily be close relatives, if person dies in a public place then it might be sometimes a person who found the body. In those cases family/relatives will be contacted and an additional form will be filled in. Comment: Under the Results it states that The questionnaire design was considered as adequate need to explain whose view this was and whether feedback was obtained from participants or whether this was the researchers view Response: Feedback was general question about how they felt and if the interview covered relevant topics for the first interviews. Comment: Did you adjust for multiple testing? Response: I assume that this question is about multiple testing of questionnaire, we did not do multiple testing. If this question is about statistics then this model is especially designed for multiple

10 timepoints - it does means that the model controls for non-independence among the repeated observations for each individual. It is also important to note that it does not drop out cases missing values. A good overview Seltman HJ (2015) Experimental Design and Analysis Chapter 15 Mixed models. Discussion You mention that response rates were not ideal but this is one of the key issues to explore in a study of this kind, and this is a key limitation of this study. Response: In very strict terms it was not ideal. In all fields of research response rates are dropping and we have presented it in light of other studies. Morton, et al. (2012) In the 21st century, what is an acceptable response rate?. Australian and New Zealand Journal of Public Health, 36: Comment: A lot of detail is given over to discussing quantitative findings, but the point of this pilot study is to look at recruitment, retention, etc ( Results of our pilot study suggest that significantly higher levels of rejection, unique reactions, responsibility and total grief ) For the same reason it seems inappropriate to explore the findings of the study in the context of other studies, because they are likely to have been studies intended to test a hypothesis about GEQ scores etc, but this study was to test the feasibility of running a larger study. Response: In the last paragraph of the introduction we mention there is confusion about what a pilot study is, whether a pilot study is the same as a feasibility study, and should hypotheses be tested within a pilot study. Nevertheless our focus is not that much on hypothesis testing, its rather on testing the primary instrument and showing its ability to measure change and differences over time, as in the discussion our main focus is to compare it to the results from the other longitudinal studies, however, there are only few studies which measure grief over time (there are more if we consider other aspects such as depression or anxiety) and no longitudinal studies using GEQ, which has been indicated. Please let us know if it needs further clarification. We did also go through a number of pilot studies published in the BMJ Open and they were testing hypotheses. Comment: Some of the syntax needs revision, eg: This pilot study is a prospective longitudinal study which enables to analyse changes and differences in the suicide and sudden death bereavement over time. Rationale to include sudden deaths as comparison/control group included since arousal of symptoms Bereaving a death that occurred Response: Accepted, text has been language edited. Reviewer: 3 Reviewer Name: Ms Ailbhe Spillane Institution and Country: National Suicide Research Foundation and the School of Public Health, University College Cork, Ireland Please state any competing interests: None declared Comment: Overall, this is a really interesting paper investigating a neglected public health concern. However, there are a number of major issues that need to be addressed: - Did the sample comprise consecutive cases from the Queensland Register or were they a selective sample? Response: They were consecutive cases, clarification has been added. - Please provide details as to why confounding factors could not be controlled for

11 Response: The pilot study is too small to test for confounding factors, further clarifications have been added. - Please provide a detailed flowchart of the recruitment process. This needs to be included for every stage of the study. Include the recruitment process for the suicide-bereaved and sudden death bereaved. Give refusals and withdrawals at each stage and reasons for refusal and withdrawal Response: We have added details to the figure. It is not possible to give reasons for all people who did not participate. - The discussion section needs to be revised. What are the implications of the study findings? Please provide a comprehensive paragraph outlining the strengths and limitations of the study. Please also provide a conclusion paragraph Response: We have added strength and weaknesses paragraph. This is a pilot study and implications of the pilot study are discussed. Implications of the study would be relevant to a full scale study. Additional comments: In the abstract and results you refer to linear mixed-methods modelling should this be linear mixed modelling? Response: Thank you, corrected. Abstract Line of the abstract need to be made clearer. Reactions is missing after somatic in this sentence. Response: Accepted, word added Line 44 of the abstract: replace fitness with appropriateness Response: Accepted, word replaced Strengths and limitations (directly after abstract) Suggest rephrasing first sentence of the strengths and limitations bullet points page 2, line 55 to: This pilot study is a prospective study which allows the opportunity to longitudinally examine any differences in grief reactions for those bereaved by suicide compared to those bereaved by sudden death Response: Accepted, sentence changed Comment: I also suggest that you emphasise how this study fills a significant gap in the literature in this point too Page 3, line 3: Suggest rephrasing this sentence to: The control group was recruited from information obtained via police forms Since you mentioned how you recruited the control group, you should mention that the suicidebereaved were identified via the Queensland register. Also, did they represent consecutive cases of suicide or was it a random sample of people on the register? State whichever it is here. Response: Thank you for suggestion. This is not quite correct, information in the QSR involves also the Police forms, we have clarified that under the methods section. Comment: Page 3, line 8: When you mention that you couldn t adjust for any confounding factors, it would be helpful if you gave two examples of some of the most important factors that you cannot control for. This will be important for the reader. Please state the authors were unable to control for confounding factors. Response: Accepted, example has been added. Introduction

12 Page 4, line 7: Suggest rephrasing people left behind to people intimately affected by suicide as you are focussing on immediate family members. I would also remove (referred to as suicide survivors in the US) as this terminology can be confusing and is rarely used outside of the US. Suggest changing this sentence to: Estimating the number of people intimately affected by a suicide is a challenging task as affects appear to differ according to quality and characteristics of the relationship with the deceased and also the age of the deceased. Response: Thank you, we did considered rephrasing, however, it is the introduction to the topic more widely. This term suicide survivor is relatively widely used (e.g. the new book by Andriessen et al (2017) Postvention in action: The international handbook of suicide bereavement support does use the term survivor and editors are not from US). Page 4, line 24: You mention people experiencing suicide often experience adverse physical, emotional and social outcomes. Include references at the end of this sentence and expand on this point further. Some useful references include; Bolton et al (2013), De Groot et al (2006), Pitman et al (2016), Pitman et al (2017) Response: Accepted, we have extended that part and we use a number of references, including systematic literature reviews. Page 4, line 27: Remove have found to and feelings of from the sentence Response: Accepted, changed Page 4, line 31: Change people bereaved by suicide show high levels to people bereaved by suicide have high levels Response: Accepted, changed Page 4, line 36: Remove (i.e., do not remain constant); however, only a. Replace over long period of time to longitudinally Response: Accepted, removed Page 4, line 53: Change Research literature indicates to Research indicates a lack of consensus regarding the definition and scope of a pilot study. Response: Accepted, changed Page 4 line 58: Change synonymous of feasibility study to synonymous with a feasibility study Response: Accepted, removed as per reviewer 2 comment Page 4, line 58: Change Leon et al write that to Leon et al defines the purpose of conducting a pilot study is to examine the feasibility of an approach that is intended to be ultimately used in a larger-scale study. Response: Accepted, removed as per reviewer 2 comment Page 5 line 12-22: This sentence is too long; break this up into two sentences Response: Accepted, changed. Page 5, line 27: You mention close relatives and in your methods you mention the inclusion criteria was immediate family members; keep the terminology consistent, use one or the other Response: Accepted, modified. Methods

13 Include the following headings in your methods section: study design, sample and recruitment, measures, statistical analysis Response: Accepted, added. Use the STROBE statement as a guideline for reporting the study using a reporting guideline is required by the journal Response: Accepted, the paper is aligned with the STROBE. There is no specific checklist for pilot studies, therefore it was not noted. Page 5, line 36: I m not convinced Figure 1 is required. Suggest that you describe the study thoroughly under study design and remove the diagram Response: We have added participant information to the figure. Describe the setting of the study where did the interviews take place, how were participants selected and how did you follow-up participants? Response: Accepted, further details added. Page 5, line 48-55: Change Rationale to include sudden deaths to People bereaved by sudden deaths were included as the control group to determine any similarities or differences in grief reactions to people bereaved by suicide Response: Sentence has modified. Recommended change does miss the point which was the sudden nature. Page 5, line 55: Change Under sudden deaths to Sudden deaths comprised accidents and sudden natural death mainly caused by cardiovascular conditions, where death occurred within hours of the development of symptoms. Response: Accepted, changed. Page 6, line 15: Change Inclusion criteria of study participants who entered the pilot: to Inclusion criteria for this pilot study were: Response: Accepted, changed. Page 6, line 27: Change Bereaved a to Bereaved by a Response: Accepted, changed. Page 6, line 46-50: You describe in this paragraph that the sudden death group were recruited via State Coroners but in the strengths and limitations directly after the abstract you describe they were identified via police forms. Please revise Response: Further clarifications have been added. All participants were recruited using police forms. The QSR and the Office of State Coroner hold police forms filled in at the time of death. (This police unit works specifically under the State coroner). Page 7, line 1: Rephrase this sentence as it is unclear Response: Accepted, changed. Page 7, line 7: You mention that the primary outcome measure was bereavement, using the Grief Experience Questionnaire (GEQ). Change this to the primary outcome measure was grief reactions, as measured by the Grief Experience Questionnaire (GEQ) Response: Accepted, changed. Results Page 9, line 12: Crombach s Alpha s should read Cronbach s Alpha s

14 Response: Accepted, changed. Page 9, line 15-27: Give score for search for explanation, unique reactions etc. in brackets? Response: Considered, however the sentences indicates to range. In terms of your t-test, give more details on these results: was there a significant difference between the two groups, and if so, for what variables? Give the respective p-values. Response: Accepted, added. Refer to my previous point about linear mixed-methods modelling should this read Linear mixedmodelling? If not, please give supporting references for this statistical technique Response: Accepted, thank you. Discussion The first paragraph needs to summarise the key findings of this study and provide commentary on how this is similar or different to other studies. Give this first paragraph the heading Principal findings. Response: Traditionally first paragraph indicates why this study is done and what did it aim. Specific comparison with other studies is provided later. Suggest changing first sentence of discussion to: Overall, there is a paucity of studies comparing outcomes following suicide bereavement to other causes of death, with some notable exceptions (provide references). Suggest changing the following sentence to: Furthermore, a very limited number of studies analysed whether outcomes following suicide bereavement changed over time. Give references for this statement. Response: Accepted, sentence changed and references added. In the second paragraph of your discussion you discuss the response rate of the study state what this is here and state the response rates of a selection of studies utilising the psychological autopsy method so the reader can see how this studies compares to others. Response: Accepted, information added. Page 10, line 53: You state However, those studies did not establish the continuing presence of this difference over time Do you mean here that these studies were not longitudinal in nature? Response: Yes, sentence modified. Page 11, line 10-17: A significant decline in the total grief score this sentence is too long, break up into two sentences. Response: Accepted, changed. Generally in this paragraph, it needs to be clearly stated whether any increases or decreases were seen across the two groups or just in the suicide or sudden death group. For example, it was stated However, there was a decline between 12 and 30 months was this across the suicide or sudden death group? Response: Accepted, information added. The paragraph starting with The results of this pilot study are obviously limited by should be given the heading Strengths and Limitations Response: Accepted, title added Strengths and Limitations Provide a few on the strengths of the study before you discuss the limitations of the study

15 Change The results of this pilot study are obviously limited by to This study has a number of limitations. Firstly the sample size is small but was considered adequate for a pilot study. Will confounding factors be adjusted for in the main study? State either way as a strength or a limitation depending on whether any factors will be adjusted for. Response: Accepted, modified. Include a concluding paragraph and label it as Conclusion Response: Accepted, added Further linguistic polishing of the text is required throughout the document Response: Accepted, linguistic editing was conducted by Dr Victoria Ross. REVIEWER REVIEW RETURNED GENERAL COMMENTS REVIEWER REVIEW RETURNED GENERAL COMMENTS VERSION 2 REVIEW Karl Andriessen School of Psychiatry, University of New South Wales, Sydney, Australia 24-Nov-2017 Thank you for submitting the revised version of your manuscript. For me, the most important results are: (i) authors were able to test the feasibility of a prospective longitudinal study, (ii) the reported measurement appears to be sufficiently sensitive to capture differences between groups over time. Just one small comment. Authors stated that language has been edited; however, there remain a few paragraphs that need to be checked. For example, page 8, lines ( which was pragmatics rule of thumb 12 for ). Also, the sentences on page 11, lines are not clear. If authors can check that, I do not have to see another revised version. It would be great to see results of a larger sample, and maybe a longer follow-up. Wishing you good luck. Alexandra Pitman UCL Division of Psychiatry, University College London, UK 05-Dec-2017 Thank you for sending me this study to review following revision. I think the key point for this paper to drive home is that a very limited number of surveys (rather than studies) have analysed whether outcomes following suicide bereavement change over time, to explore why this is the case, and to explain what this pilot study tells us about how to overcome those barriers. The other issue to emphasise is why it would be worth conducting a survey to measure changes longitudinally rather than conducting a registry-based study (because you can collect self-report measures, and because there may not be registers covering Australia).

16 REVIEWER REVIEW RETURNED However the emphasis is still on the analysis of the data collected, rather than on the feasibility of conducting the study. Whilst the findings are interesting, they are derived from a pilot sample, which by definition is not based on a power calculation. On the one hand it is stated (in the response to reviewers) that the pilot study is too small to test for confounding factors, but at the same time a lot of weight is given to the findings. One big question that remains is what proportion of the cases did not have any contactable next of kin. It is clarified that all police forms have a contact person, but that they may not necessarily be close relatives eg if it was a person who found the body. In those cases family/relatives will be contacted and an additional form will be filled in. One factor explaining the low response rate may be the difficulty in contacting the relatives in those cases. How many did that apply to? More detail needs to be given to recruitment and retention barriers, as these are the key issues that the main study is going to have to overcome to conduct this important research. The other big question is what the feedback was from the first interviews. Currently this line reads: The questionnaire design was considered as adequate by the research team based on the feedback from the first interews. However this interview data should represent a key proportion of the Results, and we are left unsure as to whether the retention was compromised by issues with the interview schedule or not. The discussion should also explore in much more detail what data will be collected in the main study to measure potential confounders In response to the point that It is also not necessarily true that certain sub-scales are unique to suicide bereavement the authors clarify that: This point comes from the authors who developed the scale. The GEQ measures two general types of grief reactions: those expected in any bereavement and those specific to suicide bereavement. (Barrrett & Scott, 1989, p.202) I am still not convinced that we can state that certain GEQ subscales are unique to suicide bereavement. The authors who developed the scale may have believed this at the time (1989) but subsequent validation (Bailley, Dunham and Krall 2000) resulted in that sub-scale being dropped. That paper commented that the original scale had been in need of revision and it seems that the so called "unique" aspects are measurable in groups bereaved by causes other than suicide, albeit differing by degree. I think the concept of unique aspects reflects inductive bias on the part of Barrett and Scott, and I think all of us who use this measure should seek not to reinforce this inductive bias. It seems that the old version of the GEQ was used in this study, and it would make more sense to use the revised validated 8 factor version (Bailley, Dunham and Krall 2000) for the main study. Ms Ailbhe Spillane National Suicide Research Foundation and the School of Public Health, University College Cork, Ireland 27-Nov-2017

17 GENERAL COMMENTS Thank you to the authors for their revision of the manuscript which reads very well. There are just a small number of very minor revisions/suggestions outstanding: - Under the 'Procedure' paragraph, the term 'police form' is repeated twice in the same sentence. - Rephrase the sentence 'The sample of the current pilot study...which was pragmatics' Well done on an excellent pilot study and I look forward to reading the results of the full-scale study in due course. VERSION 2 AUTHOR RESPONSE Reviewer: 1 Reviewer Name: Karl Andriessen Institution and Country: School of Psychiatry, University of New South Wales, Sydney, Australia Please state any competing interests: None declared Please leave your comments for the authors below Comment: Thank you for submitting the revised version of your manuscript. For me, the most important results are: (i) authors were able to test the feasibility of a prospective longitudinal study, (ii) the reported measurement appears to be sufficiently sensitive to capture differences between groups over time. Just one small comment. Authors stated that language has been edited; however, there remain a few paragraphs that need to be checked. For example, page 8, lines ( which was pragmatics rule of thumb 12 for ). Also, the sentences on page 11, lines are not clear. If authors can check that, I do not have to see another revised version. It would be great to see results of a larger sample, and maybe a longer follow-up. Wishing you good luck. Response: Thank you. We have made relevant changes. Reviewer: 2 Reviewer Name: Alexandra Pitman Institution and Country: UCL Division of Psychiatry, University College London, UK Please state any competing interests: None declared Please leave your comments for the authors below Comment: Thank you for sending me this study to review following revision. I think the key point for this paper to drive home is that a very limited number of surveys (rather than studies) have analysed whether outcomes following suicide bereavement change over time, to explore why this is the case, and to explain what this pilot study tells us about how to overcome those barriers. The other issue to emphasise is why it would be worth conducting a survey to measure changes longitudinally rather than conducting a registry-based study (because you can collect selfreport measures, and because there may not be registers covering Australia).

18 Response: Thank you. Accepted, we have changed the wording and we have extended further the importance of longitudinal survey studies. Comment: However the emphasis is still on the analysis of the data collected, rather than on the feasibility of conducting the study. Whilst the findings are interesting, they are derived from a pilot sample, which by definition is not based on a power calculation. On the one hand it is stated (in the response to reviewers) that the pilot study is too small to test for confounding factors, but at the same time a lot of weight is given to the findings. Response: We have addressed the disagreements with regards to the definition of the pilot study and there is no agreement that it is necessarily only about the feasibility. The NIHR definition of the pilot study does indicate that one can analyse data at the end of the pilot. As per our aim we included both. By NIHR Pilot studies are a version of the main study that is run in miniature to test whether the components of the main study can all work together. It is focused on the processes of the main study, for example to ensure recruitment, randomisation, treatment, and follow-up assessments all run smoothly. It will therefore resemble the main study in many respects, including an assessment of the primary outcome. In some cases this will be the first phase of the substantive study and data from the pilot phase may contribute to the final analysis; this can be referred to as an internal pilot. Or at the end of the pilot study the data may be analysed and set aside, a so-called external pilot. ( We hope that we have sufficiently increased the discussion about other parts and emphasised additional aspects so it is more balanced. Comment: One big question that remains is what proportion of the cases did not have any contactable next of kin. It is clarified that all police forms have a contact person, but that they may not necessarily be close relatives eg if it was a person who found the body. In those cases family/relatives will be contacted and an additional form will be filled in. One factor explaining the low response rate may be the difficulty in contacting the relatives in those cases. How many did that apply to? More detail needs to be given to recruitment and retention barriers, as these are the key issues that the main study is going to have to overcome to conduct this important research. Response: Apologies, possibly our explanation was not clear. If the body is not found by a family member then police still finds family member(s) to inform them about death and the main contact will be the family on the police form (called Form 1 in Queensland), but also includes the name and contact of the person who found the body. If the family is not contactable in brief period then an additional form will be filled in with the details of the family member later. We contacted family members as per our selection criteria (described), therefore it does not impact directly our response rates as we did not call strangers. The main reasons for not participating was that the potential participants were not interested or not contactable, we have added a clarification. We did change the title of the project from Suicide bereavement: Survivors in Australia to Bereavement of suicide and sudden death to improve the participation, particularly in the sudden death group; added to the text. Nevertheless, it is important to note that it is not a study about suicide or sudden death cases and when we consider bereavement then it would not be feasible to reach all close relatives. Comment: The other big question is what the feedback was from the first interviews. Currently this line reads: The questionnaire design was considered as adequate by the research team based on the feedback from the first interviews.