-->PONE-D-25-53902-->-->Cohort profile: mothers who use substances and their children in British Columbia, Canada-->-->PLOS One

Dear Dr. Nosyk,

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Academic Editor

PLOS One

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Reviewer #1: Partly

Reviewer #2: Yes

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

Reviewer #1: No

Reviewer #2: N/A

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Reviewer #1: Yes

Reviewer #2: Yes

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Reviewer #1: Yes

Reviewer #2: Yes

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-->5. Review Comments to the Author

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Reviewer #1: Reviewer Comments for Manuscript PONE-D-24-45499R3

This manuscript contains grammatical errors, awkward phrasing, and inconsistent tense usage that reduce clarity and readability. Several sentences are overly long or redundant, which weakens the logical flow of the argument. I recommend a thorough language edit to:

• Correct grammar and typographical errors.

• Ensure consistent use of past tense in the Methods and Results sections, and present tense in the Introduction and Discussion…(e.g., “effective coverage,” “crude coverage”)

• Shorten or restructure overly long sentences to improve conciseness and readability. Minor typographical errors and redundancies should be carefully polished before publication.

Suggestion: The manuscript would benefit significantly from thorough proofreading by a native English speaker or professional editing service to improve clarity and adherence to academic writing standards.

2. Abstract

• The abstract is informative but needs refinement for clarity.

• The study period is confusing: the abstract mentions June–July 2023 (1 month), while the methods section refers to September 2021–August 2022 (1 year). This inconsistency must be corrected. You have to remove … “using secondary data of mothers who received antenatal care from September 01, 2021, to August 30, 2022”. You have also change design into “retrospective cross-sectional studies”. Change…”bi variable logistic regression” → “bivariable logistic regression”;

• The results section of the abstract should align with the operational definition of effective coverage. For example, if screening for gestational diabetes is required, how does the reported 25.9% coverage reconcile with only 8.2% receiving that service?

3. Introduction

• The introduction is well contextualized, but some sentences are repetitive and could be streamlined.

• The rationale for focusing on effective coverage rather than crude coverage is well stated, but the flow could be improved by reducing redundancy.

• Consider clarifying the conceptual framework of effective coverage (need, use, quality) more succinctly.

• Suggestion: Consider adding a sentence on why West Gojjam Zone specifically was chosen—e.g., known gaps in ANC quality, high maternal mortality, or representative setting.

• Question: The authors state that “none have examined EC of ANC in our region especially in my study setting.” Were there any sub-national or facility-based ANC quality assessments that could be referenced for context?

Methods

Study design and period

The description of the study design is somewhat confusing. The manuscript currently states: “A facility-based analytical cross-sectional study design was conducted in West Gojjam public hospitals from June 30 to July 30, 2023, utilizing secondary data from mothers who received antenatal care between September 1, 2021, and August 30, 2022.”

• Since the data were extracted retrospectively from ANC charts, the design would be more accurately described as a retrospective cross-sectional study rather than “analytical cross-sectional.”

• The phrase “utilizing secondary data from mothers who received antenatal care between September 1, 2021, and August 30, 2022” is redundant here, because the study population and source of data are already explained elsewhere.

• I recommend that the authors simplify this section to report only the study design and data collection period, while clearly noting that secondary data were used. For example: “A facility-based retrospective cross-sectional study was conducted in West Gojjam public hospitals. Data were collected between June 30 and July 30, 2023, from ANC charts covering the period September 1, 2021, to August 30, 2022.”

Sampling Size Calculation

I appreciate that the authors calculated the sample size for both objectives (coverage and associated factors). However, including the full formula in the manuscript is not necessary, since you have already stated that the single population proportion formula was used.

I recommend simplifying this section by:

• Clearly stating that the sample size was calculated for both objectives.

• Indicating that the largest sample size obtained was selected as the final sample size for the study.

• Removing the redundant formula presentation, while keeping the assumptions (confidence level, margin of error, prevalence, design effect, non-response rate) clearly described.

This will make the Methods section more concise and reader friendly, while still transparent about how the sample size was determined.

Study Design and Sampling:

• The multi-stage random sampling is appropriate, but the description of selecting 3 out of 8 hospitals (38%) by “lottery” is vague. Were all hospitals eligible? Was stratification considered?

• Suggestion: Clarify whether the selection was truly random or purposive, and justify the sample size allocation.

Why were only 3 hospitals selected? Was power considered at the hospital level?

Why was a design effect of 1.5 applied? Was clustering expected, and if so, at what level? Please justify this choice.

Measurement of Effective Coverage:

The definition aligns with WHO recommendations, but the operationalization—“received all the WHO recommended interventions at least once”—may overlook frequency and timing of interventions, which is acknowledged as a limitation.

Suggestion: Briefly note how missing data on intervention timing was handled.

How was “adequately trained human power” assessed? Was it based on presence per shift, or per patient load?

Clarify whether data were extracted only from charts or supplemented with interviews.

Line 181-182. Avoid----remove…”The questionnaire was prepared in English and

182 pretested among 5% (34) of study population before the actual data collection”…this repetition/The author already included in data quality control.

Data Analysis:

The use of p<0.25 for inclusion in multivariable analysis is acceptable but should be justified given the sample size.

Suggestion: Consider also using variance inflation factors (VIF) to check multicollinearity, especially among obstetric/gynecological variables.

Question: Why were hospital-level factors (e.g., equipment, staffing) not included in the regression model?

Results:

Tables are comprehensive but could be better formatted. For example, Table 5 is split across pages Comment on Definition and Results of Effective Coverage

The manuscript defines effective coverage of ANC interventions as: pregnant women who attended four or more ANC visits and received all WHO recommended interventions at least once during their ANC follow up period.

However, the results presented raise important concerns:

• For several interventions, the proportion of women receiving them “at least once” is far below 25.9%. For example, only 8.2% received antenatal ultrasound and 8.2% were screened for gestational diabetes mellitus.

• If all WHO recommended interventions are required for effective coverage, then the reported 25.9% effective coverage seems inconsistent with these low uptake rates.

• The table also mixes “at each visit” and “at least once” indicators, which makes interpretation difficult. For example, gestational diabetes screening is reported as 25.9% “at each visit” but only 8.2% “at least once.” This needs clarification.

• The operational definition should be applied consistently: if “all WHO interventions at least once” is the criterion, then the effective coverage proportion should reflect the lowest uptake intervention (e.g., 8.2%).

Recommendations:

1. Clarify the operational definition of effective coverage — is it “all WHO interventions at least once” or “some interventions at least once”?

2. Ensure consistency between the definition and the reported results.

3. Revise the Results section to avoid contradictory figures (e.g., 25.9% vs. 8.2%).

4. Consider presenting both crude coverage (ANC 4+) and effective coverage (ANC 4+ plus all WHO interventions) separately, with clear explanation.

Discussion:

The discussion appropriately contextualizes findings within existing literature and offers plausible explanations for discrepancies.

To strengthen the impact of your manuscript, please revise the Discussion to move beyond restating the Results. Instead, focus on interpreting the clinical and public health significance of your key findings. For each major result, please address:

1. What does this mean for practice? (e.g., How should the very low rate of Gestational Diabetes Mellitus screening change clinical protocols or health worker training?)

2. What are the policy implications? (e.g., Does the finding that women with prior complications receive better coverage suggest a need to reallocate resources or change messaging to reach low-risk women?)

3. How can these findings inform action? Conclude with targeted, practical recommendations for health system managers and policymakers in your setting."

Question: The finding that prior complications increase effective coverage suggests that risk-based care is occurring. Does this imply that low-risk women are being neglected? This has important programmatic implications.

Reviewer #2: Review of "Cohort Profile: Mothers who use substances and their children in British Columbia, Canada"

16 February 2026

Lines 71-84

The authors might consider adding a brief description of substance treatment that exists outside the medical model, e.g. 12 Step and other peer-to-peer recovery programs, for clarity, and whether this is part of the studies being planned. Notably, this type of peer-to-peer delivery of services is a significant support for many people trying to recover from substance use disorders.

Line 133

Consider changing "Tobacco use was not evaluated." to "Tobacco and caffeine use was not evaluated." or something similar, for additional clarity, and to help destigmatize drug use by highlighting that the majority of Canadian adults use substances, e.g. caffeine.

Table 2

The table has two asterisked footnotes. Consider switching one of these to a different symbol, for clarity.

Lines 278-279

Consider including indigenous and immigrant status in the list of social factors that may affect health outcomes, for clarity, and to highlight these differentials.

Lines 301-304

The authors might consider adding a description of difficulty in including peer-to-peer recovery support below the text related to harm reduction services, for clarity.

Supplemental Table 2

In the footnote, consider changing "... , or In the care of ..." to "... , or in the care of ..." to correct a typographical error.

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Reviewer #1: No

Reviewer #2: No

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Cohort profile: mothers who use substances and their children in British Columbia, Canada

PONE-D-25-53902R1

Dear Dr. Nosyk,

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.

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Kind regards,

David T. Zhu

Academic Editor

PLOS One

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