PONE-D-22-01584Types, patterns and risk factors associated with drugs and substances abuse: A cross-sectional study of selected counties in KenyaPLOS ONE

Dear Dr. Okoyo,

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Based on my opinion and those of the reviewers, although the manuscript presents important theme and information it might not be interest to readers without reworking on the methodology and proper analysis of the the data. I advise that the paper be re-written considered all the issues raised by the reviewers. At this stage I can state that its acceptance for publication will depend on the outcome of the revision.==============================

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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: No

Reviewer #2: Partly

Reviewer #3: Yes

Reviewer #4: No

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

Reviewer #1: No

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: No

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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: No

Reviewer #3: Yes

Reviewer #4: No

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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: No

Reviewer #2: No

Reviewer #3: Yes

Reviewer #4: 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: Dear Authors,

I have read the manuscript and I think that it has an importan epidemiological issue, but I think that it must be rewritten

1) Title: must be revised respect to the data presented

2) Introduction: it must be rewritten considering the title: drug use abnd abuse so other considerations must be deleted

3) Methods: Experimental protocol is missing

4) Results: these are hard to understand I thin that must be completely rewrittex and as reported in results must be enclosed in a supplement file. In results you must add the data enclosed in tables

Reviewer #2: I have carefully reviewed this manuscript (ms.) which seems interesting and focused on a topic of international interest such as the use and abuse of legal and illegal drugs.

This ms. focuses on this research topic in Kenya

Although the work is dense and contains a lot of information, it presents some theoretical and methodological limitations. However, globally, this ms. allows me to conclude that it could be accepted for publication in PLOS ONE with minor changes.

This ms. needs English refinement.

ABSTRACT

Indicate the type of sampling conducted in this study.

Indicate, at least, the total N, % men or women, age range or age groups, mean and SD.

The information regarding the type of sampling and characteristics of the samples according to Figure 2 is not clear. Everything is ambiguous and imprecise.

The samplings conducted in this ms. they are non-probabilistic or for convenience. This is the most important limitation of this ms. while this poses a threat to the internal, but above all external, validity of the results found in this study. This concern could be reason enough for this ms. was rejected for publication in PLOS ONE.

INTRODUCTION

This section is properly focused and centered. The authors review previous empirical evidence found in Kenya. This is correct.

However, the authors should robustly justify the novelty, improvement or scientific advance of this ms. compared to previously published studies in Kenya. This concern is key. Authors should include this information clearly and precisely.

The authors end this section by indicating the general objective of this study. However, the authors should clearly and precisely indicate the specific objectives of this ms., as well as the hypotheses corresponding to each specific objective. Of course, these hypotheses must be formulated based on the previous empirical evidence found in Kenya, not on the results found in this study. Furthermore, these hypotheses should be robustly accepted or rejected in the Discussion section.

PARTICIPANTS

Bearing in mind Figure 2, authors should provide data for all categories or levels presented in this figure the following data: N, % male or female, age range, mean and SD). Everything is confusing.

How were outliers and missing data handled statistically?

Reviewer #3: The current manuscript describes drug and substance abuse in four counties in Kenya. The authors collected quantitative and qualitative data assessing the impact of age, educational level, gender, etc., on use and abuse of different substances in four counties and sub-counties. The authors report that there is an increase in drug and substance use in the present study compared to the one conducted in 2012. In addition, they reported that males consume drugs and substances more than females, yet the level of education did not matter. Age was another factor, showing younger adults and elderly (65 and youngers) consume more than older than 65. Overall, the manuscript contains useful information in terms of management of addiction and policy making strategies in Kenya and particularly in those counties. However, the manuscript is too lengthy and there are some information that may be deleted unless the authors need to discuss them and provide a rationale why such information is necessary to be included in the manuscript.

Major:

1. The authors state collected data but not analyzed whether the religion of the subjects impacted drug and substance abuse. If there is enough power in the study, this should analyzed and discussed.

2. Some information can be deleted or can be shortened. For example, three sentences on lines 154-158 and four sentences on lines 163-168, lines 172-178), and lines 182-186. Instead, please indicate why these counties are purposively selected since it is not obvious until later. This information also should be included in the Abstract as to why those counties were selected.

3. The authors discussed the types of drugs and concluded that heavy drugs were used less than alcohol and tobacco (line 332-335). Was this due to the cost of heavy drugs or their lack of availability as compared to alcohol? This should be discussed.

4. I think the information regarding the interviews provided in the result section can be presented in a supplemental data since this information makes the current manuscript too lengthy. However, I leave this to the discretion of the editor.

5. The number of tables and figures can be reduced. Some information is redundant.

Minor:

1. Please include other nicotine products next to cigarettes (line 83).

2. Please change psycho-stimulants to psychostimulants (Line 87).

3. Please delete the semicolon on line 277 and 279 or replace them with colon (:).

4. Please add "and" before "village elder" on line 280.

5. Please remove the comma after majority on line 302.

Reviewer #4: Thank you for your hard work dong all these types of data collection and analysis. However, I have some comments:

1. In your methodology for the quantitative part of the study the selection of the participants was not clear. You mentioned in page 5 line 148 that you used a systematic sampling technique without describing how you did that. But you mentioned that you will take houses when one at least of the household is using drugs, this is a purposive sample. We know that when one of the household is using drugs (as you also included smoking as one of these drugs) mostly more than one will be using drugs as well. So you could not calculate prevalence from this sample as this will be a biased sample.

2. On the other hand, in tables 2 and 3 you are presenting the types and frequency of drug used per age groups and per county. In the last row you are putting a total and %. You did not consider the multiple drug users in these tables and so the percent you are calculating is not a real percent.

3. You also did not mention how you asked your question to let us know if the smokers and other drug users are ever users or current users and what type of questionnaire you used. Is your questionnaire validated in the participants language or not?

4. At the end you concluded that the drug use is high with a purposive sample and without considering the multiple drug users, I could not accept your conclusion as it built on biased data.

5. Regarding the references, you used only 17 references, one of the them World Drug Report 2018 and another one was the WHO global status report 2011, and only 15 per reviewed, although in this area many publications are there.

6. Finally regarding the maps, it would be better as well to let us know where are the counties in the country.

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Reviewer #1: No

Reviewer #2: Yes: Candido J. Ingles

Reviewer #3: Yes: Kabirullah Lutfy

Reviewer #4: No

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Prevalence, types, patterns and risk factors associated with drugs and substances of use and abuse: A cross-sectional study of selected counties in Kenya

PONE-D-22-01584R1

Dear Dr. Okoyo,

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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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,

Gabriel O Dida, 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

Reviewer #3: 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: No

Reviewer #3: Yes

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

Reviewer #2: No

Reviewer #3: Yes

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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: No

Reviewer #3: Yes

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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: No

Reviewer #3: Yes

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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 authors' answers are not convincing, rigorous. Responses provided for the authors are few precise. This is not possible. The responses to reviewers are not appropiate. A convenience sampling not is possible in PLOS ONE.

Reviewer #3: The authors adequately responded to my comments of the previous version of the manuscript. I have not further comments or concerns.

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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.

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 #2: Yes: Candido J. Ingles

Reviewer #3: Yes: Kabirullah Lutfy

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