Dear Dr. Nichol,

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.

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Please note that we have only been able to secure a single reviewer to assess your manuscript. We are issuing a decision on your manuscript at this point to prevent further delays in the evaluation of your manuscript. Please be aware that the editor who handles your revised manuscript might find it necessary to invite additional reviewers to assess this work once the revised manuscript is submitted. However, we will aim to proceed on the basis of this single review if possible.

The reviewer raised a number of concerns that need attention. They would like additional descriptions and framing of MECC around established categories of intervention intensity and wider behavior change frameworks. They suggest clarifying the scope of the study by describing that the evaluation is focused on MECC HCS as a workforce intervention. The reviewer also suggests including potential downstream outcomes of the intervention and defining terminology and concepts earlier in the manuscript.

Could you please revise the manuscript to carefully address the concerns raised?

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We look forward to receiving your revised manuscript.

Kind regards,

Katherine Demi Kokkinias, Ph.D.

Staff Editor

PLOS One

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Does the manuscript provide a valid rationale for the proposed study, with clearly identified and justified research questions?

Reviewer #1: Partly

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2. Is the protocol technically sound and planned in a manner that will lead to a meaningful outcome and allow testing the stated hypotheses??>

Reviewer #1: Partly

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3. Is the methodology feasible and described in sufficient detail to allow the work to be replicable??>

Reviewer #1: Yes

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4. Have the authors described where all data underlying the findings will be made available when the study is complete??>

The PLOS Data policy

Reviewer #1: Yes

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5. Is the manuscript presented in an intelligible fashion and written in standard English??>

Reviewer #1: Yes

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Please use the space provided to explain your answers to the questions above and, if applicable, provide comments about issues authors must address before this protocol can be accepted for publication. You may also include additional comments for the author, including concerns about research or publication ethics.

You may also provide optional suggestions and comments to authors that they might find helpful in planning their study.

Reviewer #1: Question 1 feedback:

The introduction could be strengthened by more clearly situating MECC within the broader spectrum/framework of behaviour change interventions, of which it represents one component. While the protocol identifies MECC as an opportunistic brief or very brief intervention, further clarification of how this aligns with established categories of intervention intensity (e.g. very brief, brief, extended brief, and high-intensity interventions) would improve conceptual clarity.

This would help position MECC appropriately within the wider behaviour change framework and reduce potential misconceptions that it is intended to address behaviour change across all levels of need. Drawing on frameworks such as NICE guidance on individual-level behaviour change and the NHS England Behaviour Change Development Framework would strengthen this contextualisation within the rationale.

Providing this context would also enable the realist evaluation to contribute to understanding whether MECC HCS is most appropriately conceptualised as a very brief or brief intervention, or whether it aligns more closely with other levels of intervention intensity in practice.

Question 2 feedback:

The focus on “what works and for whom” is clearly articulated. However, it would be helpful to explicitly clarify that this realist evaluation is focused on MECC HCS as a workforce intervention, specifically aiming to build confidence and competence among trainees.

As currently presented, there is potential for readers to assume that the study will assess downstream patient or population-level outcomes. It would strengthen the protocol to clearly state that evaluating behavioural outcomes among recipients of MECC conversations is beyond the scope of this study (if this is the case). If the authors have considered assessing any downstream behavioural impacts, even in a limited or exploratory way, it would be useful to outline this. If not, a clear statement of scope and limitations would help manage expectations and improve transparency.

In addition, clarifying the scope in this way would also strengthen the study’s contribution by enabling the realist evaluation to more clearly position MECC HCS within the wider spectrum/framework of behaviour change interventions. This could help determine whether MECC HCS is most appropriately conceptualised as a very brief or brief intervention, or whether it aligns more closely with other levels of intervention intensity in practice.

Additional Feedback:

While the protocol clearly outlines outcomes related to confidence and competence following HCS training, it would be helpful to further clarify how these outcomes are expected to translate into actual delivery of MECC conversations in practice. At present, the link between increased capability (e.g. confidence and competence) and behavioural enactment (i.e. having MECC conversations) could be made more explicit within the programme theory and outcome framework.

Relatedly, the relatively short follow-up period (approximately eight weeks post-training) may limit the ability to assess whether HCS is embedded into routine practice over time. It would be useful to acknowledge this as a limitation, particularly given that sustained behaviour change and habit formation are key to MECC implementation.

Finally, given the range of terminology used (e.g. MECC, HCS, opportunistic behaviour change conversations), providing a clear and concise definition of these concepts early in the manuscript would improve clarity for readers, particularly those less familiar with this area.

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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.

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Reviewer #1: No

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To ensure your figures meet our technical requirements, please review our figure guidelines: https://journals.plos.org/plosone/s/figures

You may also use PLOS’s free figure tool, NAAS, to help you prepare publication quality figures: https://journals.plos.org/plosone/s/figures#loc-tools-for-figure-preparation.

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What works, for whom, and under what circumstances for recipients of training in opportunistic behaviour change conversations: a mixed methods realist evaluation protocol

PONE-D-26-12622R1

Dear Dr. Nichol,

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.

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Kind regards,

Marianne Clemence

Staff Editor

PLOS One

Additional Editor Comments (optional):

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Does the manuscript provide a valid rationale for the proposed study, with clearly identified and justified research questions?

Reviewer #1: Yes

**********

2. Is the protocol technically sound and planned in a manner that will lead to a meaningful outcome and allow testing the stated hypotheses??>

Reviewer #1: Yes

**********

3. Is the methodology feasible and described in sufficient detail to allow the work to be replicable??>

Reviewer #1: Yes

**********

4. Have the authors described where all data underlying the findings will be made available when the study is complete??>

The PLOS Data policy

Reviewer #1: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English??>

Reviewer #1: Yes

**********

Please use the space provided to explain your answers to the questions above and, if applicable, provide comments about issues authors must address before this protocol can be accepted for publication. You may also include additional comments for the author, including concerns about research or publication ethics.

You may also provide optional suggestions and comments to authors that they might find helpful in planning their study.

Reviewer #1: Thank you for taking on board my comments and feedback. I am happy to accept. All comments submitted as part of the original review have been addressed and responded with sufficiently.

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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

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