Sources of successful participant engagement in a public health research study: A focus on a Latino community

Angel Lomeli; Arleth A. Escoto; Breanna Reyes; Kayleigh Kornher; Keira Beltran-Murillo; Kathia Nuñez; Ariel Cohen; Maria Linda Burola; Isabel Villegas; Scarlet Flores; Ana Perez-Portillo; Norma Porras; Melody Torres; Linda Salgin; Kelli L. Cain; Nicole A. Stadnick; Louise C. Laurent; Borsika A. Rabin; Marva Seifert

doi:10.1371/journal.pone.0321910

Peer Review History

Original SubmissionMarch 13, 2025
2 Jun 2025 Decision Letter - Taiwo Opeyemi Aremu, Editor -->PONE-D-25-11940-->-->Sources of Successful Participant Engagement in a Public Health Research Study: a Focus on a Latino Community-->-->PLOS ONE Dear Dr. Lomeli, 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. Please submit your revised manuscript by Jul 17 2025 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, Taiwo Opeyemi Aremu Academic 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. Please provide additional details regarding participant consent. In the ethics statement in the Methods and online submission information, please ensure that you have specified (1) whether consent was informed and (2) what type you obtained (for instance, written or verbal, and if verbal, how it was documented and witnessed). If your study included minors, state whether you obtained consent from parents or guardians. If the need for consent was waived by the ethics committee, please include this information. If you are reporting a retrospective study of medical records or archived samples, please ensure that you have discussed whether all data were fully anonymized before you accessed them and/or whether the IRB or ethics committee waived the requirement for informed consent. If patients provided informed written consent to have data from their medical records used in research, please include this information. 3. Please expand the acronym “NIH/NIEHS” (as indicated in your financial disclosure) so that it states the name of your funders in full. This information should be included in your cover letter; we will change the online submission form on your behalf. 4. In the online submission form you indicate that your data is not available for proprietary reasons and have provided a contact point for accessing this data. Please note that your current contact point is a co-author on this manuscript. According to our Data Policy, the contact point must not be an author on the manuscript and must be an institutional contact, ideally not an individual. Please revise your data statement to a non-author institutional point of contact, such as a data access or ethics committee, and send this to us via return email. Please also include contact information for the third party organization, and please include the full citation of where the data can be found. 5. Please include your full ethics statement in the ‘Methods’ section of your manuscript file. In your statement, please include the full name of the IRB or ethics committee who approved or waived your study, as well as whether or not you obtained informed written or verbal consent. If consent was waived for your study, please include this information in your statement as well. 6. Please remove your figures from within your manuscript file, leaving only the individual TIFF/EPS image files, uploaded separately. These will be automatically included in the reviewers’ PDF. 7. Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice. [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: Yes 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: Yes ****** -->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: No ****** -->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: This is a well-written paper that presents important findings about engaging underrepresented communities in research. A few points to consider and/or clarify: 1. Did participants know the CO-CREATE site was a research study or were they just looking for a COVID test? The study procedures section (top of p15 describes it at first as a project site but then item 7 refers to it as a study). It also seems to be referred to as a testing site throughout the paper. I can imagine people may have a different propensity to visit the site if they know it is specifically research (vs just looking for a COVID test) for the reasons described in the introduction, and this is really important for the fundamental research question around research engagement. It would also be helpful to present how many participants did not consent to the research, as this is mentioned as a limitation. 2. A little more detail would be helpful on the free response coding methods for participant engagement, how many people were doing the coding? Was it consensus-based, and how were discrepancies handled? 3. Where the regression is described in the methods section, it says Walk Up was the most common response but this contradicts Figure 1 indicating Word of Mouth. 4. In Figure 1, it would be better to reduce the dead space between the y-axis and start of bars so they're not floating so much. Also why is the total in Figure 1 different from the total in Table 1? 5. Was the chi-squared test run using the same level of granularity for each variable as listed in the table? If so, having that level of granularity in variables across 3 categories is bound to produce significance because there are so many combinations and cells that inevitably end up with very small numbers. Consider trying to combine where it makes sense conceptually (e.g., is there something about being from Tijuana vs Chula Vista that critically differentiates people and is important to capture or is it actually just important that they're not from SY?). I also see age wasn't tested, please explain why in the text (or if it was tested and the p-value is just missing because it is included in the regression, consider revisiting the granularity of that variable or testing as a continuous variable). 6. I can appreciate the rigorous modelling approach, but it doesn't seem to align with your stated research goal of characterizing sources of participant engagement. In addition to the characterization, it seems like you're also trying to make stronger statements about how those demographic characteristics interact with the engagement mechanism. For this type of research question and how the introduction is framed, it seems like it would be more meaningful to define participant archetypes/a set of characteristics simultaneously for each effective engagement approach rather than singularly like the regression is doing. A latent class analysis may work better for this and be more straightforward to interpret (and present for the reader, the regression results are a little hard to follow and quite cumbersome with all the levels, since the interpretation of any one variable is dependent not only on the reference for that variable but also all the other variables and respective references in the model, i.e. it's not just 'compared to X reference level' it's 'compared to X reference level when variables A, B, and C are also at X, Y, Z reference levels' which can become a bit unwieldy with a bunch of categorical covariates). Reviewer #2: Although the study is generally understandable, there are places where descriptions are incomplete or not well explained. My attached file suggests a few of those modifications to improve the understanding of methods and results. ****** -->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: Dr. Alfredo L. Fort ******** [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.--> Attachments Attachment Submitted filename: PONE-D-25-11940_reviewer-AF.pdf https://doi.org/10.1371/journal.pone.0321910.r001
Revision 1
2 Sep 2025 Author Response Reviewer 1: Did participants know the CO-CREATE site was a research study or were they just looking for a COVID test? The study procedures section (top of p15 describes it at first as a project site but then item 7 refers to it as a study). It also seems to be referred to as a testing site throughout the paper. I can imagine people may have a different propensity to visit the site if they know it is specifically research (vs just looking for a COVID test) for the reasons described in the introduction, and this is really important for the fundamental research question around research engagement. It would also be helpful to present how many participants did not consent to the research, as this is mentioned as a limitation: Thank you for bringing this up. The testing site was advertised as a testing site first, and, upon testing, patients were offered participation in our study. While testing site and research study could both be used, since both are true, have modified the language when introducing this for clarity and transparency to the reader. We have also added the proportion of individuals who agreed to be a part of the study (60.8%) to the discussion section, as requested. A little more detail would be helpful on the free response coding methods for participant engagement, how many people were doing the coding? Was it consensus-based, and how were discrepancies handled?: This is a good suggestion – more information regarding how we came up with handling the free response engagement methods was added for transparency and replicability. Where the regression is described in the methods section, it says Walk Up was the most common response but this contradicts Figure 1 indicating Word of Mouth: Thank you for catching this, we have fixed the incorrect language in the text – Figure 1 is correct. In Figure 1, it would be better to reduce the dead space between the y-axis and start of bars so they're not floating so much. Also why is the total in Figure 1 different from the total in Table 1?: The different values in fig 1 and table 1 are due to table 1 describing the top three most common sources (rather than all of the sources identified). We have changed the title of the table to reflect this, since it was not clear before. Regarding the figure format, we agree that it looked awkward before due to the excessive white space – this has been fixed. Was the chi-squared test run using the same level of granularity for each variable as listed in the table? If so, having that level of granularity in variables across 3 categories is bound to produce significance because there are so many combinations and cells that inevitably end up with very small numbers. Consider trying to combine where it makes sense conceptually (e.g., is there something about being from Tijuana vs Chula Vista that critically differentiates people and is important to capture or is it actually just important that they're not from SY?). I also see age wasn't tested, please explain why in the text (or if it was tested and the p-value is just missing because it is included in the regression, consider revisiting the granularity of that variable or testing as a continuous variable): Yes, the chi-squares tests were run as shown in Table 1. Regarding age, it was run as a continuous variable at first (was significant at p<.01) but was changed to a categorical variable for ease of interpretability for the table and follow-up analysis. As a categorical variable, it was run and also significant at p <.01 but, as you mentioned, was not included in the Table – this was an error and has been fixed and added to the table. As suggested, city was consolidated into three categories – San Ysidro resident, not a San Ysidro resident, and prefer not to answer. I can appreciate the rigorous modelling approach, but it doesn't seem to align with your stated research goal of characterizing sources of participant engagement. In addition to the characterization, it seems like you're also trying to make stronger statements about how those demographic characteristics interact with the engagement mechanism. For this type of research question and how the introduction is framed, it seems like it would be more meaningful to define participant archetypes/a set of characteristics simultaneously for each effective engagement approach rather than singularly like the regression is doing. A latent class analysis may work better for this and be more straightforward to interpret (and present for the reader, the regression results are a little hard to follow and quite cumbersome with all the levels, since the interpretation of any one variable is dependent not only on the reference for that variable but also all the other variables and respective references in the model, i.e. it's not just 'compared to X reference level' it's 'compared to X reference level when variables A, B, and C are also at X, Y, Z reference levels' which can become a bit unwieldy with a bunch of categorical covariates): Thank you for this comment. We agree that a multinomial regression model as a final model might not fully capture specific subgroups that our research question is aiming to look at. We had originally considered a latent class analysis, among many different approaches, as a potential model to use for our analysis. Some other approaches we thought of included reducing the outcome variable to two levels (a more conventional categorical regression model) to make statistcal inferences less cumbersome – which would end up being Clinic/Provider vs. Word of Mouth, the two top methods. However, this would leave out the third most common choice which has a high frequency (495) – something we felt was important to include, especially given the next (fourth) highest response was at 78. When looking at the assumptions and model fit for an LCA, we found that the nature of our dataset showed that the model is not a good fit. For example, when calculating the Bayesian information criterion, we found that its value was lowest for the single class model and increased significantly and linearly as the classes increased from 2-5. Lastly, we have a lot of subgroups among each of the variables of interest (as you had pointed out in an earlier comment). Regarding consolidation, we were able to consolidate the city variable to be a comparison of living in San Ysidro vs. not in San Ysidro since, as you mentioned, the purpose of the study is able to be achieved with this consolidation. The chi-square and logistic regression model were re-run since this change would have changed the statistics – this is reflected in both tables in the manuscript. Reviewer 2: This might need a definition, to make it clearer for the reader: Thank you for pointing this out, while this is explained in the main text, we see why it is not clear in the abstract – this has been rectified. Where in? The one near San Diego, CA? Needs to be fully introduced. It would be good to provide general socio-demographic characteristics of the city, so that the reader has an idea of the generic "context" of the study area: More context and specific demographics were added in order to better introduce the region where the study took place, an important factor in introducing the study setting. Put the term first in quotations, and then explain what they are in English, for the benefit of the reader: This is a great point – we put promotores in italics, for uniformity across the paper since they were also used in the discussion when Spanish words were mentioned. We also slightly expanded on the role and model of the promotores for more context. Important to describe where are the other areas... Which type? How far away, what characteristics of this place, etc., needed: As suggested by another reviewer, we have revised the levels of the city variable to only include San Ysidro resident, non-San Ysidro resident, and prefer not to answer. However, we completely agree that it would be a good idea to include an explanation as to where our variable levels were collected including the possible symptoms that participants could have reported which would have resulted in them being classified as “symptomatic” in this study. This has been added to the methods section. Important percentage; tricky that there is no answer: If this is referring to the overall percentage of “prefer not to say”, for instance, they can be found in the fifth column under the total, along with their counts for each subgroup in each variable. Needs to be put more clearer which is the OR, etc., as narrated in the text: The title of each column was changed to reflect that they are presenting odds ratios. Also, for more clarity, the note under the table was changed to be more specific to what the comparison is. compared to...?: Thank you for catching this – this has been rectified. Any reasons, given that there were open ended questions asked?: We are unsure… our discussion after this sentence describes potential explanations backed by other studies, including one that precedes this one, who have shown a low rate of primary care and preventative care for men compared to women. Also physical aspects such as being out and about at younger ages than at older ages...other possible factors?: Perhaps, however, the study found that older age participants were actually more likely to walk up to our site, not the other way around. https://doi.org/10.1371/journal.pone.0321910.r002
22 Sep 2025 Decision Letter - Taiwo Opeyemi Aremu, Editor <p>Sources of successful participant engagement in a public health research study: a focus on a Latino community PONE-D-25-11940R1 Dear Dr. Lomeli, 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 will be generated when your article is formally accepted. Please note, if your institution has a publishing partnership with PLOS and your article meets the relevant criteria, all or part of your publication costs will be covered. Please make sure your user information is up-to-date by logging into Editorial Manager at Editorial Manager® and clicking the ‘Update My Information' link at the top of the page. For questions related to billing, please contact billing support . 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, Taiwo Opeyemi Aremu, MD, MPH, PhD Academic Editor PLOS ONE Additional Editor Comments (optional): Reviewer #1: Reviewer #2: 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 #1: All comments have been addressed 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 #1: Yes Reviewer #2: Yes ****** -->3. Has the statistical analysis been performed appropriately and rigorously? --> Reviewer #1: Yes 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 #1: Yes 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 #1: Yes 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 #1: Thank you for your thoughtful responses and edits. All of my comments have been addressed and I have no further notes. Reviewer #2: Thanks for submitting the revised manuscript, improving several aspects for readers to easily understand the study and the study to be well and fully described. Please see the attached file for only a few final suggestions to clarify descriptions. ****** -->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 #1: No Reviewer #2: Yes: Dr. Alfredo L. Fort ******** Attachments Attachment Submitted filename: PONE-D-25-11940_R1_reviewer-AF.pdf https://doi.org/10.1371/journal.pone.0321910.r003
Formally Accepted
Acceptance Letter - Taiwo Opeyemi Aremu, Editor PONE-D-25-11940R1 PLOS ONE Dear Dr. Lomeli, I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now being handed over to our production team. At this stage, our production department will prepare your paper for publication. This includes ensuring the following: * All references, tables, and figures are properly cited * All relevant supporting information is included in the manuscript submission, * There are no issues that prevent the paper from being properly typeset You will receive further instructions from the production team, including instructions on how to review your proof when it is ready. Please keep in mind that we are working through a large volume of accepted articles, so please give us a few days to review your paper and let you know the next and final steps. Lastly, 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. You will receive an invoice from PLOS for your publication fee after your manuscript has reached the completed accept phase. If you receive an email requesting payment before acceptance or for any other service, this may be a phishing scheme. Learn how to identify phishing emails and protect your accounts at https://explore.plos.org/phishing. If we can help with anything else, please email us at customercare@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. Taiwo Opeyemi Aremu Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0321910.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 .