Investigating the associations between intimate partner violence and nutritional status of women in Zimbabwe

Jeanette Iman’ishimwe Mukamana; Pamela Machakanja; Hajo Zeeb; Sanni Yaya; Nicholas Kofi Adjei

doi:10.1371/journal.pone.0272038

Peer Review History

Original SubmissionApril 5, 2021
11 Jan 2022 Decision Letter - Lorena Verduci, Editor PONE-D-21-11105 Investigating the associations between intimate partner violence and nutritional status of women in Zimbabwe PLOS ONE Dear Dr. Adjei, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. The manuscript has been evaluated by two reviewers, and their comments are available below. The reviewers have raised a number of concerns that need attention. They feel the introduction should outline the state of the art regarding studies on IPV and nutritional status. The reviewers also request improvements to the reporting of methodological aspects of the study, for example, regarding the use of the full Revised Conflict Tactics (CTs) instrument for the IPV measurement. Could you please revise the manuscript to carefully address the concerns raised? Please submit your revised manuscript by Feb 21 2022 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. Please include the following items when submitting your revised manuscript: A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'. A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'. An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'. If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter. If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols. We look forward to receiving your revised manuscript. Kind regards, Lorena Verduci Staff Editor PLOS ONE Journal Requirements: When submitting your revision, we need you to address these additional requirements. 1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf 2. Thank you for stating the following financial disclosure: "No" At this time, please address the following queries: a) Please clarify the sources of funding (financial or material support) for your study. List the grants or organizations that supported your study, including funding received from your institution. b) State what role the funders took in the study. If the funders had no role in your study, please state: “The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.” c) If any authors received a salary from any of your funders, please state which authors and which funders. d) If you did not receive any funding for this study, please state: “The authors received no specific funding for this work.” Please include your amended statements within your cover letter; we will change the online submission form on your behalf. 3. Thank you for stating the following in your Competing Interests section: "No" Please complete your Competing Interests on the online submission form to state any Competing Interests. If you have no competing interests, please state "The authors have declared that no competing interests exist.", as detailed online in our guide for authors at http://journals.plos.org/plosone/s/submit-now This information should be included in your cover letter; we will change the online submission form on your behalf. 4. PLOS requires an ORCID iD for the corresponding author in Editorial Manager on papers submitted after December 6th, 2016. Please ensure that you have an ORCID iD and that it is validated in Editorial Manager. To do this, go to ‘Update my Information’ (in the upper left-hand corner of the main menu), and click on the Fetch/Validate link next to the ORCID field. This will take you to the ORCID site and allow you to create a new iD or authenticate a pre-existing iD in Editorial Manager. Please see the following video for instructions on linking an ORCID iD to your Editorial Manager account: https://www.youtube.com/watch?v=_xcclfuvtxQ [Note: HTML markup is below. Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Partly Reviewer #2: Yes ******** 2. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes Reviewer #2: Yes ****** 3. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: No Reviewer #2: No ****** 4. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes Reviewer #2: Yes ****** 5. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: The thematic of the manuscript is interesting and relevant, given the scarcity of studies on the relationship between IPV and inadequate nutritional status. However, for publication the paper needs some improvements. ABSTRACT I suggest revising the wording of the passage “Relative to normal weight, women who had ever experienced at least one form of IPV (i.e., physical, emotional, or sexual) were more likely to be obese (aOR = 2.59; 95% CI = 1.05–6.39). Women’s exposure to any form of intimate partner violence was not significantly associated with the likelihood of being underweight or overweight relative to normal weight.”, because it is confusing since in the conclusion of the abstract, you state that “we found a positive relationship between IPV and obesity.” INTRODUCTION The introduction lacks information about the state of the art regarding studies on intimate partner violence and nutritional status in order to point out what has been studied and the gaps. METHODS The authors could make it clear whether the full Revised Conflict Tactics (CTs) instrument or single questions were used for the IPV measurement. If the authors used single questions, this should be included as one of the limitations of the paper and how this form of data collection impacts the findings. Is the marital status only these two answer options (married, cohabiting)? And women who are dating and the partner does not reside at the household RESULT The main finding of the paper which is the positive association of emotional IPV with obesity is "erased" by the other analyses which involve the possibility of having 1 of the two types of violence (physical OR emotional; physical OR sexual, ...). I think the analysis could be more objective and contemplate the role of each type of violence separately or their coexistence. Table 1: insert 95% confidence interval Table 2: insert 95% confidence interval In table 2 it would be more interesting to bring the specific types of violence (emotional, physical and sexual) and the co-occurrence emotional AND physical, emotional AND sexual and this way on Table 3 it would be more interesting to bring the specific types of violence (emotional, physical and sexual) and the co-occurrence emotional AND physical, emotional AND sexual and this way on Figure 1 It would be interesting to bring the proportion of physical, emotional or sexual violence against women of reproductive age (15–49 years) by nutritional status by year 2005/2006, 108 2010/2011, and 2015 DICUSSION The discussion could delve into the possible mechanisms that may explain the relationship found (IPV positively associated with obesity). Insert as a limitation how to measure the exposure of interest (IPV). Reviewer #2: Introduction The introduction is short and I think this is a good option. However, I suggest contextualizing better the IPV situation in Zimbabwe. Method The covariates measurement could be described in the method A theoretical model (DAG) could be shown in the methods section Table 1 – Table 1 could inform the number of women in each category, and the confidence interval. Table 2 – table 2 could present the prevalence by BMI status ****** 6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: No Reviewer #2: Yes:** Tatiana Henriques Leite [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step. https://doi.org/10.1371/journal.pone.0272038.r001
Revision 1
3 Apr 2022 Author Response Reviewer #1: Overall comments The thematic of the manuscript is interesting and relevant, given the scarcity of studies on the relationship between IPV and inadequate nutritional status. Response: Thank you. 1.1 Major Comments: Abstract 1.1a. I suggest revising the wording of the passage “Relative to normal weight, women who had ever experienced at least one form of IPV (i.e., physical, emotional, or sexual) were more likely to be obese (aOR = 2.59; 95% CI = 1.05–6.39). Women’s exposure to any form of intimate partner violence was not significantly associated with the likelihood of being underweight or overweight relative to normal weight.”, because it is confusing since, in the conclusion of the abstract, you state that “we found a positive relationship between IPV and obesity.” Response: Thank you for this comment, we have now revised the wording in the abstract. Page 1, line39-43: “Relative to normal weight, women who had ever experienced at least one form of IPV (i.e., physical, emotional, or sexual) were more likely to be obese (aOR = 2.59; 95% CI = 1.05–6.39). Women’s exposure to any form of intimate partner violence was not significantly associated with the likelihood of being underweight or overweight relative to normal weight.” And Line 45-46: “between exposure to at least one form IPV and obesity.” 1.2. Comment: Introduction 1.2a.The introduction lacks information about the state of the art regarding studies on intimate partner violence and nutritional status in order to point out what has been studied and the gaps. Response: Thank you. We have added more literature to point out what has been studied and the existing gaps regarding research on intimate partner violence and nutritional status. Page 2, line 68-73: “The prevalence of IPV is high in developing countries [1]. However, there is evidence of cross-country variations [20,21], where Zimbabwe has been found to be one of the countries in sub-Saharan Africa with the highest prevalence of IPV [21,22]. It is estimated that approximately 35% of women had experienced physical violence from the age of 15 and 14% had experienced sexual violence [23]. In a recent study in Zimbabwe, Mukamana and colleagues found a substantial rise in the prevalence of IPV from 40.9% in 2010 to 43.1% in 2015 [1].” Line 83-86: “In Zimbabwe, for instance, a recent study showed an increase in the prevalence of overweight and obesity from 25.0% in 2005 to 36.6% in 2015 [36]. The authors also observed socioeconomic and demographic differences in overweight and obesity among women of reproductive age.” 1.3. Comment: Methods 1.3ai.The authors could make it clear whether the full Revised Conflict Tactics (CTs) instrument or single questions were used for the IPV measurement. If the authors used single questions, this should be included as one of the limitations of the paper and how this form of data collection impacts the findings. Response: Thank you, the Modified Conflict Tactic scale was used for IPV measurement, in line with previous studies. Page 3, line 132-135: “We used the measurement of IPV in the surveys that was based on the modified Conflict Tactics (CTS2).” 1.3aii.Is the marital status only these two answer options (married, cohabiting)? And women who are dating and the partner does not reside at the household. Response: Thanks. This study considerered only those in unions (living together with their partners) – i.e., either married or cohabiting. 1.4. Comments: Results 1.4ai. RESULT The main finding of the paper which is the positive association of emotional IPV with obesity is "erased" by the other analyses which involve the possibility of having 1 of the two types of violence (physical OR emotional; physical OR sexual, ...). I think the analysis could be more objective and contemplate the role of each type of violence separately or their coexistence. Response: Thank you for your comment. We have now assessed the co-occurrence of the various forms of violence. (see table 1, 2 and 3) and the result section. Page 5-6, line 217-219: “Similarly, we found that women who had ever experienced all three forms of IPV more likely to be obese (aOR = 2.83; 95% CI = 1.28–6.25) relative to normal-weight women.” 1.4aii. Table 1: insert 95% confidence interval Response: We have now added 95% confidence interval (See table1) 1.4aiii.Table 2: insert 95% confidence interval Response: Thanks. We have now added 95% confidence interval (See table1) 1.4aiv. In table 2 it would be more interesting to bring the specific types of violence (emotional, physical, and sexual) and the co-occurrence emotional AND physical, emotional AND sexual and this way on. Response: Thank you for your comment. We have now included the co-occurrences of the various forms of violence (table 2) 1.4av.Table 3. It would be more interesting to bring the specific types of violence (emotional, physical, and sexual) and the co-occurrence emotional AND physical, emotional AND sexual and this way on Response: Thanks. We have now included the co-occurrences of the various forms of violence (table 3) 1.4avi. Figure 1 It would be interesting to bring the proportion of physical, emotional, or sexual violence against women of reproductive age (15–49 years) by nutritional status the year 2005/2006, 2010/2011, and 2015 Response: Thank you. We have now included the proportion of physical, emotional, or sexual violence against women of reproductive age (15–49 years) by nutritional status the year 2005/2006, 2010/2011, and 2015 ( See figure 2). 1.5 Comments: Discussion 1.5ai.The discussion could delve into the possible mechanisms that may explain the relationship found (IPV positively associated with obesity) . Response: Thanks for this comment: we have now added more possible mechanisms to explain the positive association of IPV with obesity. Page 6, line 252-259: “Prior research have linked stressors including IPV with obesity [82]. It has been shown that stressful conditions may lead to the development of obesity through several mechanisms and pathways including increased hormone release [83,84], which can increase food cravings. [85,86]. In a study, Torres and Nowson (2007) found increased rate of obesity among people who face mild stressors [18]. This may be due to overeating and consumption of food that are in high calories or sugar [87,88], which may affect behavioural patterns such as sleep and physical activity [89].” 1.5aii. Insert as a limitation how to measure the exposure of interest (IPV). Response: Thank you. We have included this suggestion in the limitation section. Page 7, line 293-294: “Fourth, DHS measures self-reported IPV, and this may under estimate IPV among participants in our sample” Reviewer #2: Major Comments 1.1. Comment: Introduction 1.1a.The introduction is short and I think this is a good option. However, I suggest contextualizing better the IPV situation in Zimbabwe. Response: Thank you for your comment. We have revised the introduction to contextualize the IPV situation in Zimbabwe and added more literature to contextualize this issue in Zimbabwe. Page 2, line 68-73: “The prevalence of IPV is high in developing countries [1]. However, there is evidence of cross-country variations [20,21], where Zimbabwe has been found to be one of the countries in sub-Saharan Africa with the highest prevalence of IPV [21,22]. It is estimated that approximately 35% of women had experienced physical violence from the age of 15 and 14% had experienced sexual violence [23]. In a recent study in Zimbabwe, Mukamana and colleagues found a substantial rise in the prevalence of IPV from 40.9% in 2010 to 43.1% in 2015 [1].” 1.2 Comment: Method 1.2a.The covariates measurement could be described in the method. Response: Thank you. We have now described the computed measures. Page 4, line 153-155. “The wealth index in the DHS is usually computed using durable goods, household characteristics and basic services” 1.2b.A theoretical model (DAG) could be shown in the methods section Response: We have now included DAG in the method section (See figure 1) 1.2c.Table 1 – Table 1 could inform the number of women in each category, and the confidence interval. Response: Thank you, we have included the number of women in each category, and the confidence interval (see table 1) 1.2d.Table 2 – table 2 could present the prevalence by BMI status Response: Thank you for your comment. Table 2 is presented by BMI status (i.e., over weight and obesity vs the other groups). We feel that dichotomising it is easier for interpretation. Attachments Attachment Submitted filename: Response to Reviewers.docx https://doi.org/10.1371/journal.pone.0272038.r002
13 Jul 2022 Decision Letter - Carla Pegoraro, Editor Investigating the associations between intimate partner violence and nutritional status of women in Zimbabwe PONE-D-21-11105R1 Dear Dr. Adjei, We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements. Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication. An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org. If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. Kind regards, Carla Pegoraro Division Editor PLOS ONE Additional Editor Comments (optional): Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation. Reviewer #2: All comments have been addressed ******** 2. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #2: Yes ****** 3. Has the statistical analysis been performed appropriately and rigorously? Reviewer #2: Yes ****** 4. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #2: Yes ****** 5. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #2: Yes ****** 6. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #2: I have been giving a review before. The authors attend my request. However, the DAG is not exactly what I was expecting. So, I recommend two websites to the Authors. It is not a mandatory request. But the confounders are been addressed with this technique currently. https://cran.r-project.org/web/packages/ggdag/vignettes/intro-to-dags.html http://www.dagitty.net/dags.html ****** 7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #2: Yes: Tatiana Henriques Leite ******** https://doi.org/10.1371/journal.pone.0272038.r003
Formally Accepted
15 Jul 2022 Acceptance Letter - Carla Pegoraro, Editor PONE-D-21-11105R1 Investigating the associations between intimate partner violence and nutritional status of women in Zimbabwe Dear Dr. Adjei: I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department. If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org. If we can help with anything else, please email us at plosone@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Dr Carla Pegoraro Staff Editor PLOS ONE https://doi.org/10.1371/journal.pone.0272038.r004

Open letter on the publication of peer review reports

PLOS recognizes the benefits of transparency in the peer review process. Therefore, we enable the publication of all of the content of peer review and author responses alongside final, published articles. Reviewers remain anonymous, unless they choose to reveal their names.

We encourage other journals to join us in this initiative. We hope that our action inspires the community, including researchers, research funders, and research institutions, to recognize the benefits of published peer review reports for all parts of the research system.

Learn more at ASAPbio .