Dear Dr Chamie,

Thank you for submitting your manuscript entitled "A Randomized Trial of Financial Incentives and Deposit Contracts to Promote HIV Retesting" for consideration by PLOS Medicine.

Your manuscript has now been evaluated by the PLOS Medicine editorial staff and I am writing to let you know that we would like to send your submission out for external assessment.

However, before we can send your manuscript to reviewers, we need you to complete your submission by providing the metadata that is required for full assessment. To this end, please login to Editorial Manager where you will find the paper in the 'Submissions Needing Revisions' folder on your homepage. Please click 'Revise Submission' from the Action Links and complete all additional questions in the submission questionnaire.

Please re-submit your manuscript within two working days, i.e. by .

Login to Editorial Manager here: https://www.editorialmanager.com/pmedicine

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Feel free to email us at plosmedicine@plos.org if you have any queries relating to your submission.

Kind regards,

Richard Turner, PhD

Senior Editor, PLOS Medicine

rturner@plos.org

Dear Dr. Chamie,

Thank you very much for submitting your manuscript "A Randomized Trial of Financial Incentives and Deposit Contracts to Promote HIV Retesting" (PMEDICINE-D-21-00078R1) for consideration at PLOS Medicine.

Your paper was evaluated by an academic editor with relevant expertise and sent to independent reviewers, including a statistical reviewer. The reviews are appended at the bottom of this email and any accompanying reviewer attachments can be seen via the link below:

[LINK]

In light of these reviews, we will not be able to accept the manuscript for publication in the journal in its current form, but we would like to invite you to submit a revised version that addresses the reviewers' and editors' comments fully. You will appreciate that we cannot make a decision about publication until we have seen the revised manuscript and your response, and we expect to seek re-review by one or more of the reviewers.

In revising the manuscript for further consideration, your revisions should address the specific points made by each reviewer and the editors. Please also check the guidelines for revised papers at http://journals.plos.org/plosmedicine/s/revising-your-manuscript for any that apply to your paper. In your rebuttal letter you should indicate your response to the reviewers' and editors' comments, the changes you have made in the manuscript, and include either an excerpt of the revised text or the location (eg: page and line number) where each change can be found. Please submit a clean version of the paper as the main article file; a version with changes marked should be uploaded as a marked up manuscript.

In addition, we request that you upload any figures associated with your paper as individual TIF or EPS files with 300dpi resolution at resubmission; please read our figure guidelines for more information on our requirements: http://journals.plos.org/plosmedicine/s/figures. While revising your submission, please upload your figure files to the 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. 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 us at PLOSMedicine@plos.org.

We hope to receive your revised manuscript by Mar 23 2021 11:59PM. Please email us (plosmedicine@plos.org) if you have any questions or concerns.

***Please note while forming your response, if your article is accepted, you may have the opportunity to make the peer review history publicly available. The record will include editor decision letters (with reviews) and your responses to reviewer comments. If eligible, we will contact you to opt in or out.***

We ask every co-author listed on the manuscript to fill in a contributing author statement, making sure to declare all competing interests. If any of the co-authors have not filled in the statement, we will remind them to do so when the paper is revised. If all statements are not completed in a timely fashion this could hold up the re-review process. If new competing interests are declared later in the revision process, this may also hold up the submission. Should there be a problem getting one of your co-authors to fill in a statement we will be in contact. YOU MUST NOT ADD OR REMOVE AUTHORS UNLESS YOU HAVE ALERTED THE EDITOR HANDLING THE MANUSCRIPT TO THE CHANGE AND THEY SPECIFICALLY HAVE AGREED TO IT. You can see our competing interests policy here: http://journals.plos.org/plosmedicine/s/competing-interests.

Please use the following link to submit the revised manuscript:

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Your article can be found in the "Submissions Needing Revision" folder.

To enhance the reproducibility of your results, we recommend that you deposit your laboratory protocols in protocols.io, where a protocol can be assigned its own identifier (DOI) such that it can be cited independently in the future. For instructions see http://journals.plos.org/plosmedicine/s/submission-guidelines#loc-methods.

Please ensure that the paper adheres to the PLOS Data Availability Policy (see http://journals.plos.org/plosmedicine/s/data-availability), which requires that all data underlying the study's findings be provided in a repository or as Supporting Information. For data residing with a third party, authors are required to provide instructions with contact information for obtaining the data. PLOS journals do not allow statements supported by "data not shown" or "unpublished results." For such statements, authors must provide supporting data or cite public sources that include it.

Please let me know if you have any questions, and we look forward to receiving your revised manuscript.

Sincerely,

Richard Turner, PhD

Senior Editor, PLOS Medicine

rturner@plos.org

-----------------------------------------------------------

Requests from the editors:

Please adapt your title so that the study descriptor ("a randomized trial" falls after a colon); and include the country name.

In the abstract and results section, please quote effect sizes and 95% CI for the primary endpoint findings.

Please quote study dates in your abstract.

Please add a few final sentence to the "Methods and findings" subsection of your abstract, beginning "Study limitations include ..." or similar and quoting 2-3 of the study's main limitations.

After the abstract, we will need to ask you to add a new and accessible "Author summary" section in non-identical prose. You may find it helpful to consult one or two recent research papers published in PLOS Medicine to get a sense of the preferred style.

Please refer to figure 2 as the "Participant flowchart" or similar, rather than "CONSORT diagram".

We believe that CONSORT discourages statistical tests at baseline in randomized trials, and ask that you remove these from table 1.

At line 261 and any other instances in the paper, please avoid "nearly three-fold", instead quoting actual numbers.

Throughout the text, please style reference call-outs as follows: "... HIV transmission [1,2]. Similarly ... " (noting the absence of spaces within the square brackets).

Please remove the information on study funding from the end of the main text. In the event of publication, this information will appear in the article metadata, via entries in the submission form.

In the reference list, please ensure that all references have full access details, e.g., reference 15.

Please ensure that journal names are abbreviated consistently.

Please add a completed CONSORT checklist, labelled "S1_CONSORT_Checklist" or similar and referred to as such in the Methods section. In the checklist, please refer to individual items by section (e.g., "Methods") and paragraph number rather than by page or line numbers, as the latter generally change in the event of publication.

Please include the study protocol as a supplementary document, referred to in your Methods section, unless this is published.

Comments from the reviewers:

*** Reviewer #1:

[See attachment]

Michael Dewey

*** Reviewer #2:

This is an interesting, well conducted and well reported study.

My main comment is about the fact that the take-up for the deposit contract appeared to be quite low. I was not necessarily surprised by this finding given the low average income in the study setting and therefore the predictably low ability to save. I am surprised that this did not appear as a major constraint for the feasibility of study. Specifically, I would have liked the authors to compare their finding in their pilot study (Chamie G, Ndyabakira A, Marson KG, Emperador DM, Kamya MR, Havlir DV, et al. A pilot randomized trial of incentive strategies to promote HIV retesting in rural Uganda. PLoS ONE. 2020;15(5):e0233600.) with their findings in the present study. Did they manage to get higher uptake of the deposit contracts in the pilot study? Apparently yes, since in the pilot study 93% made deposits, but only 14% in the current study. Why and what might explain the differences in uptake between the pilot study and current study? This seems to be a key point to discuss.

Given the low uptake for the deposit contracts in the current study, very little can be concluded about the comparison between cash incentives and deposit contracts, which, I suppose, was the main objective of the study. The remaining result is about the effectiveness of the cash incentives, but that effectiveness has already been established (see Lee R, Cui RR, Muessig KE, Thirumurthy H, Tucker JD. Incentivizing HIV/STI Testing: A Systematic Review of the Literature. AIDS Behav. 2013.)

Minor comment:

I am surprised not to have found one of the first study testing incentives for HIV testing in the reference list:

Thornton RL. The Demand for, and Impact of, Learning HIV Status. Am Econ Rev. 2008;98(5):1829-63.

*** Reviewer #3:

A Randomized Trial of Financial Incentives and Deposit Contracts to Promote HIV Retesting

Manuscript Number: PMEDICINE-D-21-00078R1

This manuscript reports the results of a three-group randomized, controlled trial to determine the effectiveness of 1) financial incentives and 2) deposit contracts vs. 3) control in achieving HIV re-testing at both 3 and 6 months post-randomization among people at high risk for contracting HIV in southwestern Uganda. Eligible individuals were those who presented for an evaluation and who were 18-59 years of age, tested negative for HIV, and reported at least one of the following risk factors in the prior 12 months: 1) >1 partner; 2) a known HIV-infected partner; 3) a history of a sexually transmitted infection; or 4) paid or received money or gifts in exchange for sex. Self-report (at screening/baseline) and HIV testing data (screening/baseline and follow-up) were collected over a ~6-month observation period.

Strengths of this study are its large sample size, three-arm randomized and controlled design, rapid recruitment period, and high-risk target population. The paper is well organized, clearly written and will add to the body of literature on the effectiveness of financial incentives and deposit contracts. This reviewer found no major issues and only a handful of minor issues (described below) that authors may consider addressing.

Major Issues: None

Minor Issues:

1) Lines 134-135: Consider including a brief description of measures assessed via the baseline questionnaire. If not feasible due to space limitations, consider referring readers to Table 1 for a list of the measures. Also, consider clarifying whether any follow-up questionnaire was administered at 3- and 6-month follow-ups.

2) Line 147: Figure 1 refers to "cash transfer", yet this term is not addressed within the text. Does this payment correspond to the "one-time reimbursement" of $2.70 paid to individuals who completed the screening/baseline evaluation (as mentioned in line 118)?

a) If yes, then I recommend using parallel terminology and $ amount in the text and figure to add clarity.

b) If no, then I recommend the term, "cash transfer", be briefly defined or described within the text prior to being used in the figure.

3) Line 188: The recruitment period is clearly describing. For clarity and context, consider clearly stating the full study observation period and/or "stop date" (last date on which data were collected for last randomized participant).

4) Lines 265-266: The phrase, "Further cost-effectiveness modeling…" sounds like some cost-effectiveness modeling may already have been performed and additional modeling is recommended. Is this the case?

a) If yes, please briefly present results of any cost-effectiveness modeling already performed.

b) If no, please eliminate "Further" and start the sentence with "Cost-effectiveness modeling…" to avoid confusion.

5) Line 332: Consider addressing the short observation period (only 6 months) as a study limitation, particularly because lines 66-67 indicate that Uganda Ministry of Health recommends HIV retesting every 3 months for "key populations" which (presumably) includes the high-risk individuals recruited for this study.

***

Any attachments provided with reviews can be seen via the following link:

[LINK]

Attachments

Attachment

Submitted filename: chamie.pdf

Dear Dr. Chamie,

Thank you very much for re-submitting your manuscript "Financial Incentives and Deposit Contracts to Promote HIV Retesting in Uganda: a randomized trial" (PMEDICINE-D-21-00078R2) for consideration at PLOS Medicine.

I have discussed the paper with our academic editor and it was also seen again by three reviewers. I am pleased to tell you that, provided the remaining editorial and production issues are dealt with, we expect to be able to accept the paper for publication in the journal.

The remaining issues that need to be addressed are listed at the end of this email. Any accompanying reviewer attachments can be seen via the link below. Please take these into account before resubmitting your manuscript:

[LINK]

***Please note while forming your response, if your article is accepted, you may have the opportunity to make the peer review history publicly available. The record will include editor decision letters (with reviews) and your responses to reviewer comments. If eligible, we will contact you to opt in or out.***

In revising the manuscript for further consideration here, please ensure you address the specific points made by each reviewer and the editors. In your rebuttal letter you should indicate your response to the reviewers' and editors' comments and the changes you have made in the manuscript. Please submit a clean version of the paper as the main article file. A version with changes marked must also be uploaded as a marked up manuscript file.

Please also check the guidelines for revised papers at http://journals.plos.org/plosmedicine/s/revising-your-manuscript for any that apply to your paper. If you haven't already, we ask that you provide a short, non-technical Author Summary of your research to make findings accessible to a wide audience that includes both scientists and non-scientists. The Author Summary should immediately follow the Abstract in your revised manuscript. This text is subject to editorial change and should be distinct from the scientific abstract.

We hope to receive your revised manuscript within 1 week. Please email us (plosmedicine@plos.org) if you have any questions or concerns.

We ask every co-author listed on the manuscript to fill in a contributing author statement. If any of the co-authors have not filled in the statement, we will remind them to do so when the paper is revised. If all statements are not completed in a timely fashion this could hold up the re-review process. Should there be a problem getting one of your co-authors to fill in a statement we will be in contact. YOU MUST NOT ADD OR REMOVE AUTHORS UNLESS YOU HAVE ALERTED THE EDITOR HANDLING THE MANUSCRIPT TO THE CHANGE AND THEY SPECIFICALLY HAVE AGREED TO IT.

Please ensure that the paper adheres to the PLOS Data Availability Policy (see http://journals.plos.org/plosmedicine/s/data-availability), which requires that all data underlying the study's findings be provided in a repository or as Supporting Information. For data residing with a third party, authors are required to provide instructions with contact information for obtaining the data. PLOS journals do not allow statements supported by "data not shown" or "unpublished results." For such statements, authors must provide supporting data or cite public sources that include it.

To enhance the reproducibility of your results, we recommend that you deposit your laboratory protocols in protocols.io, where a protocol can be assigned its own identifier (DOI) such that it can be cited independently in the future. Additionally, PLOS ONE offers an option to publish peer-reviewed clinical study protocols. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols

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.

Please note, when your manuscript is accepted, an uncorrected proof of your manuscript will be published online ahead of the final version, unless you've already opted out via the online submission form. If, for any reason, you do not want an earlier version of your manuscript published online or are unsure if you have already indicated as such, please let the journal staff know immediately at plosmedicine@plos.org.

Please let me know if you have any questions, and we look forward to receiving the revised manuscript shortly.   

Sincerely,

Richard Turner, PhD

Senior Editor, PLOS Medicine

rturner@plos.org

------------------------------------------------------------

Requests from Editors:

Please finalize the arrangements for data deposition and release.

Please add a sentence, say, at line 51 to quote the number, and distribution by study arm, of seroconversions.

Throughout the text, please move reference call-outs before punctuation (e.g., " ... HIV transmission [1,2].").

In the reference list, please abbreviate journal names consistently (e.g., "PLoS Med.").

Comments from Reviewers:

***Reviewer #1:

The authors have addressed my points and have clearer up the point about the randomisation.

Michael Dewey

*** Reviewer #2:

Thank you for your responses to my comments.

I remain convinced of the relevance of my second comment:

"Given the low uptake for the deposit contracts in the current study, very little can be concluded

about the comparison between cash incentives and deposit contracts, which, I suppose, was the

main objective of the study. The remaining result is about the effectiveness of the cash

incentives, but that effectiveness has already been established (see Lee R, Cui RR, Muessig KE,

Thirumurthy H, Tucker JD. Incentivizing HIV/STI Testing: A Systematic Review of the Literature.

AIDS Behav. 2013.) "

Your answer is technically correct but does not convince me that the results from this randomized control trial are sufficiently novel and important to be published in PLoS Medicine.

*** Reviewer #3:

The "minor issues" that I raised were satisfactorily addressed in this revision.

***

Any attachments provided with reviews can be seen via the following link:

[LINK]

Dear Dr Chamie, 

On behalf of my colleagues and the Academic Editor, Dr Barnabas, I am pleased to inform you that we have agreed to publish your manuscript "Financial Incentives and Deposit Contracts to Promote HIV Retesting in Uganda: a randomized trial" (PMEDICINE-D-21-00078R3) in PLOS Medicine.

Before your manuscript can be formally accepted you will need to complete some formatting changes, which you will receive in a follow up email. Please be aware that it may take several days for you to receive this email; during this time no action is required by you. Once you have received these formatting requests, please note that your manuscript will not be scheduled for publication until you have made the required changes.

In the meantime, please log into Editorial Manager at http://www.editorialmanager.com/pmedicine/, click the "Update My Information" link at the top of the page, and update your user information to ensure an efficient production process. 

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To enhance the reproducibility of your results, we recommend that you deposit your laboratory protocols in protocols.io, where a protocol can be assigned its own identifier (DOI) such that it can be cited independently in the future. Additionally, PLOS ONE offers an option to publish peer-reviewed clinical study protocols. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols

Thank you again for submitting to PLOS Medicine. We look forward to publishing your paper. 

Sincerely, 

Richard Turner, PhD 

Senior Editor, PLOS Medicine

rturner@plos.org