PONE-D-20-35871

Impact of Iron Fortification on Anaemia and Iron Deficiency among Pre-school Children Living in Rural Ghana

PLOS ONE

Dear Dr. Tchum,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit, and indeed both reviewers are positive regarding your work. However, this latter 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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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

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

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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

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

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Reviewer #1: Yes

Reviewer #2: Yes

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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: My compliments to the authors, this is a well written manuscript about a properly designed and explained study.

I have a few questions/remarks though:

- The authors mention the definitions of anaemia, ID etc in the statistics paragraph of the Methods section. I suggest to make a separate paragraph. Also, please add references regarding the definitions and cut-off levels. Have the authors used WHO guidelines? I believe not in the case of ZPP. And what is adjusted ZPP (Table 4?) Can they also elaborate on the acute phase aspect of ZPP?

- In the Results section and baseline characteristics table, it is technically wrong to perform statistical analyses on the baseline characteristics of a randomized trial. Any unsimilar data have to be coincidences if randomization was properly done. Suggest to remove the p-values and just note that both groups are comparable.

- Was the cluster randomization performed with a computer? Please elaborate.

- The authors mention in the Discussion the hypothesis that malaria affects hepcidin and hereby iron homeostasis bij leading to upregulated hepcidin with followed lower iron status. However, the authors do not have hepcidin levels right? If not, this information is not very relevant for this article.

- I miss discussion on the impact of the multi fortification instead of just plane iron supplementation, for example, vit C also stimulates iron absorption. Please elaborate a bit.

Reviewer #2: The manuscript PONE-D-20-35871 titled “Impact of iron fortification on anemia and iron deficiency among pre-school children living in rural Ghana” assesses in a randomized fashion the impact of long-term prophylactic iron (ferrous fumarate), administered as a micronutrient powder along with vitamin A, ascorbic acid and zinc, on the risk of iron deficiency (ID) and iron deficiency anemia (IDA) in Ghanaian infants and toddlers aged 6 to 35 months living in a rural malaria endemic area. The results clearly show that the use of the selected iron-fortified MNP reduced anemia, ID and IDA in this setting compared to a similar MNP without iron. The manuscript is well-written with few minor grammatical mistakes.

Specific comments:

1. A flow diagram would be useful, with further explanation of the reasons for exclusion of 262 children.

2. Figure 1 does not contribute much and should be removed.

3. There is a serious mistake in Table 3. The number (percentage of children with outcome, i.e., anemia, ID and IDA) has been mixed up for the two study groups, i.e., the results of the iron group are reported in the non-iron group and vice versa. Please, correct.

4. The phrase acute phase status on the title of Table 4 is confusing. I would change the title of Table 4 to: Effect of MNP on hemoglobin, anemia, iron biomarkers and CRP among study participants. Moreover, Table 4 has several minor mistakes. The difference of transferrin in baseline between the two study groups (iron versus non-iron) is -5.15 instead of -5.16. In the same column, the difference in baseline IDA between the two groups is 0.35 (not 0.36) and the difference in CRP, also in the same column, is 0.11 instead of 0.10.

5. The authors should stick throughout the manuscript with either the British or the American way of English writing. If haemoglobin and haemolysis are used, then haeme should also be used instead of heme.

6. I believe that the reference on line 106, page 5 should be reference No. 25 and not No. 26.

7. In line 58, page 3, please remove the word of. As an of intervention… should be as an intervention.

8. In line 66, page 3 uninfected red erythrocytes, should be changed to uninfected erythrocytes. The authors can write red cells or erythrocytes but certainly not red erythrocytes.

9. In line 124, page 6, the sentence starting from Sachets containing without or with should be corrected to Sachets without or with iron. Please, remove the word containing.

10. The first sentence of page 9 (line 186), should read: The characteristics of the study population have previously been described elsewhere.

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Reviewer #1: No

Reviewer #2: Yes: Elpis Mantadakis, MD, PhD

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Impact of Iron Fortification on Anaemia and Iron Deficiency among Pre-school Children Living in Rural Ghana

PONE-D-20-35871R1

Dear Dr. Tchum,

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,

Francois Blachier, PhD

Academic 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

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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: The revised manuscript is substantially better than the original submission. The authors addressed all my comments adequately.

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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.

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Reviewer #2: Yes: Elpis Mantadakis, MD, PhD