Process evaluation of a hybrid effectiveness-implementation, pragmatic, cluster randomised controlled trial (IMPULSE) to improve psychosocial treatment of patients with psychotic-spectrum disorders in Southeast Europe

Tamara Pemovska; Nikolina Jovanović; Tamara Radojičić; Silvana Markovska Simoska; Fjolla Ramadani; Sanja Andrić Petrović; Emina Karamehić; Biljana Blazhevska Stoilkovska; Jon Konjufca; Stefan Jerotić; Alma Džubur Kulenović; Lidija Injac Stevović; Jill J. Francis

doi:10.1371/journal.pone.0338408

Peer Review History

Original SubmissionMay 7, 2025
6 Jun 2025 Decision Letter - Cheong Kim, Editor Dear Dr. Jovanovic, 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 21 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. 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, Cheong Kim 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 note that in order to use the direct billing option the corresponding author must be affiliated with the chosen institute. Please either amend your manuscript to change the affiliation or corresponding author, or email us at plosone@plos.org with a request to remove this option. 3. 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. 4. Your ethics statement should only appear in the Methods section of your manuscript. If your ethics statement is written in any section besides the Methods, please move it to the Methods section and delete it from any other section. Please ensure that your ethics statement is included in your manuscript, as the ethics statement entered into the online submission form will not be published alongside your manuscript. Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. Is the manuscript technically sound, and do the data support the conclusions? 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 Reviewer #1: Yes Reviewer #2: Yes ****** 4. Is the manuscript presented in an intelligible fashion and written in standard English??> Reviewer #1: Yes Reviewer #2: Yes ****** Reviewer #1: Scientific and social relevance: addresses psychosocial interventions in resource-limited contexts. Robust methodology: use of mixed methods with qualitative and quantitative data collection, triangulation of sources, and use of recognized theoretical frameworks. Clarity in presentation: logically structured and well-organized, with tables and detailed descriptions. Suggestion for additional clarity: although it already includes many details, some tables could be moved to supplementary material to improve the flow of the main text. Technical terms: ensure that all less familiar terms, such as “intervention fidelity” and “solution-focused approach,” are briefly explained within the body of the text for readers less familiar with them. Reviewer #2: A clearer match between the stated aims and the main findings would improve the text. Although acceptance, faithfulness, and contextual influence are described in the study, the discussion should further explain how these connect to the primary IMPULSE trial's observed clinical outcomes. Purposive sampling is acceptable, but more information is required to understand how site variety and demographic diversity were maintained. Transparency could be improved by including a table that summarizes participant characteristics by site. ****** 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: No ******** [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.0338408.r001
Revision 1
27 Jul 2025 Author Response 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 Response to reviewers: We have revised the manuscript where needed to align with PLOS ONE’s style requirements and those for file naming, using the templates provided. 2. Please note that in order to use the direct billing option the corresponding author must be affiliated with the chosen institute. Please either amend your manuscript to change the affiliation or corresponding author, or email us at plosone@plos.org with a request to remove this option. Response to reviewers: The correct affiliation of the corresponding author is as noted in the manuscript ‘Centre for Psychiatry and Mental Health, Wolfson Institute of Population Health, Queen Mary University of London, London, United Kingdom’ 3. 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. Response to reviewers: The dataset (which includes individual interview transcripts) used and analysed during the current study is not publicly available due to participant confidentiality and ethical considerations. The authors do not have the ethical approval to make data immediately available to the public. The study did not include explicit consent for public data sharing. The data are part of the IMPULSE trial, whose chief investigator was Dr Nikolina Jovanović (the co-author previously listed as the contact point regarding data). We have revised the data statement to a non-author institutional contact in line with PLOS ONE’s data policy, and data access requests may be directed to Queen Mary University of London, Wolfson Institute of Population Health; email: wiph-admin@qmul.ac.uk. 4. Your ethics statement should only appear in the Methods section of your manuscript. If your ethics statement is written in any section besides the Methods, please move it to the Methods section and delete it from any other section. Please ensure that your ethics statement is included in your manuscript, as the ethics statement entered into the online submission form will not be published alongside your manuscript. Response to reviewers: The ethics statement appears only in the Methods section of the manuscript. 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 Response to reviewers: We thank both reviewers for affirming that the manuscript is technically sound and that the data support the conclusions. 2. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes Reviewer #2: Yes Response to reviewers: We appreciate the reviewers’ positive assessment of the statistical analyses conducted. 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: Yes Reviewer #2: Yes Response to reviewers: Thank you. As noted above, we have amended the Data Availability Statement to better reflect PLOS ONE’s policies and to provide a non-author institutional contact. 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 Response to reviewers: We are grateful for this positive feedback. 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: Scientific and social relevance: addresses psychosocial interventions in resource-limited contexts. Robust methodology: use of mixed methods with qualitative and quantitative data collection, triangulation of sources, and use of recognized theoretical frameworks. Clarity in presentation: logically structured and well-organized, with tables and detailed descriptions. Suggestion for additional clarity: although it already includes many details, some tables could be moved to supplementary material to improve the flow of the main text. Technical terms: ensure that all less familiar terms, such as “intervention fidelity” and “solution-focused approach,” are briefly explained within the body of the text for readers less familiar with them. Response to reviewers: Thank you for the positive feedback and suggestions. We have addressed them as follows: • Moved Table 5 (occurrence and attendance of all intervention sessions) and Table 6 (frequency of action items agreed during the DIALOG+ sessions) to the existing supplementary material related to intervention fidelity findings (S4 Table) to improve the flow of the main text. • The term “intervention fidelity” is already briefly explained in the Abstract and Introduction. We have now also added a short clarification for “solution-focused approach” at first mention in the Introduction and Methods section to aid reader understanding (see pages 5 and 7 in the revised manuscript, respectively). Reviewer #2: A clearer match between the stated aims and the main findings would improve the text. Although acceptance, faithfulness, and contextual influence are described in the study, the discussion should further explain how these connect to the primary IMPULSE trial's observed clinical outcomes. Purposive sampling is acceptable, but more information is required to understand how site variety and demographic diversity were maintained. Transparency could be improved by including a table that summarizes participant characteristics by site. Response to reviewers: We appreciate these thoughtful comments and have addressed them as follows: • In the Discussion section, we have included how the process evaluation findings regarding acceptability, fidelity and the role of context relate to the IMPULSE trial’s observed effect of the intervention on patients’ quality of life (see page 36). • The manuscript already includes details on the purposive sampling approach, specifying efforts to ensure variation in participants for interviews regarding intervention acceptability (page 9). To further improve transparency, we have now included additional information in the supplementary material (Table S3), which presents characteristics of interviewed patients (age, gender, diagnosis, level of engagement with DIALOG+) by site. Associated edits in the manuscript are made on page 19. 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 thischoice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: No Reviewer #2: No Response to reviewers: Noted - we respect and acknowledge the reviewers' preferences. Attachments Attachment Submitted filename: Response to Reviewers_V2.0_27.07.2025.docx https://doi.org/10.1371/journal.pone.0338408.r002
24 Nov 2025 Decision Letter - Cheong Kim, Editor Process evaluation of a hybrid effectiveness-implementation, pragmatic, cluster randomised controlled trial (IMPULSE) to improve psychosocial treatment of patients with psychotic-spectrum disorders in Southeast Europe PONE-D-25-20318R1 Dear Dr. Jovanovic, 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, Cheong Kim Academic Editor PLOS ONE Additional Editor Comments (optional): Reviewers' comments: Reviewer's Responses to Questions Comments to the Author Reviewer #1: All comments have been addressed Reviewer #3: All comments have been addressed ******** 2. Is the manuscript technically sound, and do the data support the conclusions??> Reviewer #1: Yes Reviewer #3: Yes ****** 3. Has the statistical analysis been performed appropriately and rigorously? -->?> Reviewer #1: Yes Reviewer #3: Yes ****** 4. Have the authors made all data underlying the findings in their manuscript fully available??> The PLOS Data policy Reviewer #1: Yes Reviewer #3: Yes ****** 5. Is the manuscript presented in an intelligible fashion and written in standard English??> Reviewer #1: Yes Reviewer #3: Yes ****** Reviewer #1: The revised manuscript fully meets the journal's requirements and satisfactorily addresses the reviewers' comments. Its methodological clarity, relevance of the topic, and rigor in execution make it a valuable contribution to the field of mental health in resource-limited settings. Reviewer #3: The manuscript provides an insightful and rigorously conducted process evaluation of the IMPULSE hybrid effectiveness-implementation, pragmatic cluster RCT aiming to improve psychosocial treatment for individuals with psychotic-spectrum disorders across Southeast Europe. The topic is of high relevance, and the study meaningfully addresses a well-recognized gap in mental health implementation research in low- and middle-resource settings. Strengths include: A clear theoretical underpinning using established implementation frameworks. Strong integration of mixed-methods data, with transparent reporting of analytical procedures. Thoughtful examination of contextual influences and implementation variability across countries. Clear articulation of how implementation outcomes informed interpretation of the trial’s effectiveness results. High overall coherence, readability, and adherence to PLOS ONE reporting expectations. ****** 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 #3: No ******** https://doi.org/10.1371/journal.pone.0338408.r003
Formally Accepted
Acceptance Letter - Cheong Kim, Editor PONE-D-25-20318R1 PLOS One Dear Dr. Jovanovic, 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. Cheong Kim Academic Editor PLOS One https://doi.org/10.1371/journal.pone.0338408.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 .