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Kaimen Rigor review

Liquefied Petroleum Gas or Biomass Cooking and Severe Infant Pneumonia.

McCollum ED, McCracken JP, Kirby MA, Grajeda LM, Hossen S, Moulton LH, Simkovich SM, Goodman-Palmer D, Rosa G, Mukeshimana A, Balakrishnan K, Thangavel G, Garg SS, Castañaza A, Thompson LM, Diaz-Artiga A, Papageorghiou AT, Davila-Roman VG, Underhill LJ, Hartinger SM, Williams KN, Nicolaou L, Chang HH, Lovvorn AE, Rosenthal JP, Pillarisetti A, Ye W, Naeher LP, Johnson MA, Waller LA, Jabbarzadeh S, Wang J, Chen Y, Steenland K, Clasen TF, Peel JL, Checkley W, HAPIN Investigators

DOI: 10.1056/NEJMoa2305681
Record issued: 2026-08-16
Engine: 7.39.0
Exported: 2026-09-21

Prepared by Alpha1. This document is confidential: it is intended for the recipient it was shared with and must not be redistributed. The live record at alpha1science.com/verify/58a10c44-bafc-46f0-abbe-be1ea4ab419a is authoritative.

Kaimen Rigor review

Kaimen Rigor reviewed

1 / 5

Critical — a demonstrable failure

Interventional Study

Critical

High-priority

How this rating was calculated

Started at 5★ — deductions

StatisticsImpossible or misreported statistic ×2−2★
StatisticsPrinted percentage does not match its own count (capped) ×4−0.25★
ReportingData & code availability partially met−0.25★
CitationsUnresolved reference−0.25★

A demonstrable critical failure caps the rating at the minimum, regardless of the deductions above.

Model-reported confidence: highReviewer agreement: highEngine: 7.39.0Source: full text

Not verified in this report

The numeric-impossibility checks (GRIM/GRIMMER/DEBIT/SPRITE) did not run: 12 reported means were read, and their group size is not stated where the values are printed (this source has no machine-readable table structure). These checks need the count the mean was averaged over, so none was performed.
No data or code availability links were detected to verify.

Biggest issues2 demonstrable

01Printed percentage does not match its own countdemonstrable
criticalArithmeticrecomputedFull detail
58.9% does not match the reported count 904/1515
“904 (58.9%)”
Table 1
02Printed percentage does not match its own countdemonstrable
criticalArithmeticrecomputedFull detail
53.8% does not match the reported count 820/1503
“820 (53.8%)”
Table 1
03Printed percentage does not match its own count
mediumArithmeticrecomputedFull detail
26.2% does not match the reported count 403/1515
“403 (26.2%)”
Table 1
04Printed percentage does not match its own count
mediumArithmeticrecomputedFull detail
27.8% does not match the reported count 424/1503
“424 (27.8%)”
Table 1
05Printed percentage does not match its own count
mediumArithmeticrecomputedFull detail
13.5% does not match the reported count 208/1515
“208 (13.5%)”
Table 1
06Printed percentage does not match its own count
mediumArithmeticrecomputedFull detail
17% does not match the reported count 259/1503
“259 (17.0%)”
Table 1

Findings by category

201ArithmeticNumerical inconsistencies 102OverreachOverstated conclusions 03AuthenticityNone found 104DisclosureReporting gaps 105AvailabilityBroken references and links · partly checked 06Copyedit3 minor suggestions

This Kaimen Rigor review uses Kaimen Rigor reviewers trained on a curated corpus of high-fidelity and retracted papers, with expert supervision and curation. It can still make mistakes; verify each finding against the source before relying on it.

This is a well-conducted and well-reported multi-country RCT with a strong scientific premise, rigorous design, and transparent reporting. The main weaknesses are the vague data availability statement and the lack of explicit naming of statistical software and reporting guideline, which are minor reporting gaps rather than substantive flaws.

Both reviewers classified the study as interventional (RCT), and I adopt that classification. The evaluation covered all eight dimensions; several sub-criteria were marked not applicable (e.g., species/strain, housing, IACUC, cell line authentication) because this is a human clinical trial. The statistics verification component could only recompute a subset of tests, and the inconsistency count should be interpreted with that coverage caveat in mind.

Numerical inconsistencies

2 findings · worst critical

Values that contradict each other or are impossible for the stated sample: recomputed p-values and test statistics, GRIM/GRIMMER checks on summary numbers, percentages against their own counts, totals against their parts, and estimates against their own confidence intervals.

Summary statistic impossible for the stated N (GRIM/GRIMMER)Recomputed
Printed percentage does not match its own countRecomputed

Recomputed 2 tests: 2 consistent, 0 inconsistent; 2 via agent-written checks. 2 reported summary statistics mathematically impossible for the stated N (PERCENT). 4 printed percentages that do not match their own count.

Numeric forensics— values impossible for the reported sample size

PERCENT
58.9% does not match the reported count 904/1515
“904 (58.9%)”
Table 1
PERCENT
53.8% does not match the reported count 820/1503
“820 (53.8%)”
Table 1
PERCENT
26.2% does not match the reported count 403/1515
“403 (26.2%)”
Table 1
PERCENT
27.8% does not match the reported count 424/1503
“424 (27.8%)”
Table 1
PERCENT
13.5% does not match the reported count 208/1515
“208 (13.5%)”
Table 1
PERCENT
17% does not match the reported count 259/1503
“259 (17.0%)”
Table 1

Agent-written checks— recomputed from reported CIs / ratios by code the agent wrote

CONSISTENTreported p = .810 · recomputed p = .844Reviewer 1
Recompute p-value for primary IRR from CI
“incidence rate ratio (98.7% CI) 0.96 (0.64, 1.44; p=0.81)”
Find in source
Taken as given: The CI is a 98.75% confidence interval for the incidence rate ratio.; The estimate is 0.96 and the CI bounds are 0.64 and 1.44.; The p-value is two-sided.
Method: Used pCI function to derive p-value from estimate and confidence interval for a ratio.
How we recomputed it: pCI(0.96, 0.64, 1.44, 1)
CONSISTENTreported p = .810 · recomputed p = .844Reviewer 2
Primary outcome IRR and p-value from Poisson GEE
“incidence rate ratio (98.7% CI) 0.96 (0.64, 1.44; p=0.81)”
Find in source
Taken as given: The 0.96 is the IRR estimate; The 0.64 and 1.44 are the 98.75% CI bounds; The CI is on the log scale (ratio); The p-value is from the same model (Poisson GEE)
Method: p-value derived from the reported IRR and 98.75% CI using the normal approximation on the log scale.
How we recomputed it: pCI(0.96, 0.64, 1.44, 1)

Overstated conclusions

1 finding · worst low

Conclusions that reach past what the paper's own results support — including a significance claim that no longer holds when the statistic is recomputed, and efficacy resting on an unvalidated surrogate endpoint.

Conclusions only partially backed by the presented evidenceAssessed

4 major claims checked against the paper's own evidence: 1 only partially supported (evidence backs part of the claim; gaps or caveats remain); the rest adequately supported.

partialReviewer 2
Unvented LPG cookstoves are unlikely to reduce severe infant pneumonia.
The claim is partially supported by the null primary result, but the wide confidence intervals (0.64-1.44) mean clinically important effects cannot be excluded, as the authors themselves note in the limitations.
Evidence: Primary outcome: IRR 0.96, 98.75% CI 0.64-1.44. The authors state in the Discussion: 'The wide confidence intervals around our effect estimates mean that we cannot exclude clinically important reductions or increases in severe pneumonia risk.'
Our findings are consistent with null findings from a cluster randomized trial in Ghana of a similar cookstove, indicating that unvented LPG cookstoves are unlikely to reduce severe infant pneumonia.
Discussion ¶1reviewer’s wording
supportedReviewers 1, 2
There was no significant difference in severe pneumonia incidence among infants of women randomized to LPG compared to biomass-burning cookstoves.
The primary outcome analysis shows an IRR of 0.96 with a wide CI including 1, and the p-value is 0.81, supporting the null finding.
Evidence: Primary outcome analysis: IRR 0.96 (98.75% CI 0.64, 1.44; p=0.81).
“There was no significant difference in severe pneumonia incidence among infants of women randomized to LPG compared to biomass-burning cookstoves.”
ConclusionFind in source
supportedReviewers 1, 2
High intervention uptake led to reduced PM2.5 personal exposures among children.
The paper reports median PM2.5 exposures of 24.2 vs 66.0 μg/m3 in intervention and control groups, respectively, indicating a substantial reduction.
Evidence: Results: intervention median 24.2 μg/m3 (IQR 17.8, 36.4); control median 66.0 μg/m3 (IQR 35.2, 132.0).
High intervention uptake led to reduced PM2.5 personal exposures among children (intervention median 24.2 μg/m3 (interquartile range (IQR) 17.8, 36.4); control median 66.0 μg/m3 (IQR 35.2, 132.0).
Abstractreviewer’s wording
supportedReviewers 1, 2
No severe adverse events associated with the intervention were reported.
The paper reports burns in a small number of infants but none classified as serious adverse events.
Evidence: Adverse Events section: Burns reported by three infants (0.2%) in intervention and seven (0.5%) in control; no burn classified as serious adverse event.
No burn was classified as a serious adverse event.
Resultsreviewer’s wording

Data authenticity concerns

None found

An adversarial read for patterns associated with data that may not be genuine: results that look too clean, implausibly large effects, duplicated data or images, and methods that do not match the results reported.

Checked — nothing surfaced.

Reporting gaps

1 finding · worst medium

Required detail the manuscript never states — study design, biological variables, ethics approval and consent, key resources, statistical reporting, data and code availability, and overall transparency.

Data/code availability incompleteAssessed

Eight Dimensions7 pass · 1 warn

The introduction cites prior observational evidence (refs 1-4) and notes that prior RCTs of cleaner cooking interventions did not find an effect on child pneumonia, while discussing potential reasons (insufficient exposure reduction, case definition specificity, statistical power). The paper then states that HAPIN was designed to address these limitations. The limitations of prior research are explicitly acknowledged and the rationale for the current study is logically presented.

Sub-criteria

prior work citedADEQUATE

premise rationaleADEQUATE

limitations addressedADEQUATE

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

The paper establishes a clear scientific premise with prior work cited and a logical rationale for the trial.

Evidence

paraphrase[Introduction, paragraph 1]

“Observational studies suggest fine particulate air pollution (PM2.5) exposure from incomplete solid fuel combustion is a risk factor for pneumonia.”

paraphrase[Introduction, paragraph 2]

“The Household Air Pollution Intervention Network (HAPIN) trial was designed to address these limitations in assessing whether cooking with an unvented liquefied petroleum gas (LPG) stove and fuel during pregnancy and the offspring’s first year of life, compared to biomass, reduced severe infant pneumonia incidence and other health outcomes.”

PASSReviewer 2· 95% conf

The paper clearly establishes the scientific premise by citing prior observational studies linking household air pollution to pneumonia, noting the null results from prior RCTs, and explaining how the HAPIN trial was designed to address limitations of previous work.

Evidence

paraphrase[Introduction, paragraphs 1-3]

“Observational studies suggest fine particulate air pollution (PM2.5) exposure from incomplete solid fuel combustion is a risk factor for pneumonia. ... To date, randomized controlled trials (RCTs) of cleaner cooking interventions have not found an effect on primary child pneumonia outcomes. However, it is unclear if lack of benefit stemmed from insufficiently lowered pollutant levels due to inadequate cookstove intervention uptake or performance, lack of specificity in pneumonia case definitions, or low statistical power.”

paraphrase[Introduction, paragraph 3]

“The Household Air Pollution Intervention Network (HAPIN) trial was designed to address these limitations in assessing whether cooking with an unvented liquefied petroleum gas (LPG) stove and fuel during pregnancy and the offspring's first year of life, compared to biomass, reduced severe infant pneumonia incidence and other health outcomes.”

Randomization method is described (1:1, stratified in India and Peru), and the unit is the pregnant woman. Blinding is described: participants and field staff were not blinded, but investigators were masked during data analysis. A power analysis is provided with a sample size of 3,200 to detect a 36% reduction with 80% power. Inclusion/exclusion criteria are pre-specified. Outlier handling is addressed through missing data assumptions and sensitivity analyses. Controls are the biomass group. Independent replication is not applicable for a single pivotal trial.

Sub-criteria

controlsADEQUATE

power analysisADEQUATE

blinding levelsADEQUATE

outlier handlingADEQUATE

randomization unitADEQUATE

inclusion exclusionADEQUATE

randomization methodADEQUATE

replicate distinctionN/A

independent replicationN/A

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 95% conf

The trial design is rigorous with appropriate randomization, blinding of investigators, power analysis, and pre-specified outcomes.

Evidence

“We randomized participants to intervention and control groups on a 1:1 basis. India and Peru used stratified randomization to ensure balance between two and six distinct geographical study areas, respectively.”

MethodsFind in source

“While the intervention assignment could not be blinded to participants and field staff, all investigators were masked to study group at the time of data cleaning, image interpretation, or data analysis.”

MethodsFind in source

“we estimated a sample of 3,200 pregnant women would provide 80% power to detect a 36% reduction in severe pneumonia incidence between study arms assuming a baseline rate of 9/100 infant-years using an α of 0.0125”

Statistical analysisFind in source

PASSReviewer 2· 95% conf

The study design is rigorous: a multi-country RCT with clear randomization, blinding of investigators, a pre-specified power analysis, explicit inclusion/exclusion criteria, and appropriate handling of the primary analysis (ITT).

Evidence

MethodsFind in source

paraphrase[Methods, Statistical analysis]

“Based on available evidence, we estimated a sample of 3,200 pregnant women would provide 80% power to detect a 36% reduction in severe pneumonia incidence between study arms assuming a baseline rate of 9/100 infant-years using an α of 0.0125 (multiple hypothesis testing for four trial outcomes).”

Table 2 reports child sex (male/female) with counts and percentages. Maternal age, education, gestational age, and other demographics are reported in Table 1. Age/weight/health status is covered by gestational age, birth weight-for-age z-score, and vaccination status. Demographics are comprehensively reported. Species/strain/housing are not applicable for a human trial.

Sub-criteria

demographicsADEQUATE

sex reportedADEQUATE

sex justifiedN/A

age weight healthADEQUATE

housing conditionsN/A

species strain sourceN/A

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

Biological variables are well reported for a human trial, including sex, age, and demographics.

Evidence

“Child sex, n (%) | Male | 800 (52.1%) | 787 (51.6%)”

Table 2Find in source

“Mother’s age (years) at baseline | Mean (SD) | 25.3 (4.4) | 25.4 (4.5)”

Table 1Find in source

PASSReviewer 2· 95% conf

Key biological variables are well-reported: child sex, maternal age, gestational age, and other demographics are provided in tables. Sex is reported for infants, and both sexes are included, so sex justification is not applicable. Species/strain/housing are not applicable for a human trial.

Evidence

“Child sex, n (%) | Male | 800 (52.1%) | 787 (51.6%) | | Female | 736 (47.9%) | 738 (48.4%)”

Table 2Find in source

paraphrase[Table 1]

“Mother's age (years) at baseline | Mean (SD) | 25.3 (4.4) | 25.4 (4.5)”

The protocol was approved by all investigator-affiliated institutional review boards, and participants provided written informed consent. Regulatory compliance is implied through adherence to standard ethical practices, though not explicitly named. The DSMB oversight is described.

Sub-criteria

iacuc statementN/A

informed consentADEQUATE

irb ethics statementADEQUATE

regulatory complianceADEQUATE

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 95% conf

Ethical approvals and consent are adequately reported.

Evidence

paraphrase[Methods, Oversight]

“The protocol, available at NEJM.org (http://NEJM.org), was approved by all investigator-affiliated institutional review boards (see).”

“Participants provided written informed consent.”

MethodsFind in source

PASSReviewer 2· 95% conf

Ethical approvals are adequately reported: the protocol was approved by all investigator-affiliated IRBs, written informed consent was obtained, and regulatory compliance is implied through the oversight section.

Evidence

paraphrase[Methods, Oversight]

“The protocol, available at NEJM.org, was approved by all investigator-affiliated institutional review boards (see Supplementary Material). Participants provided written informed consent.”

“An independent data and safety monitoring board (DSMB) monitored safety and efficacy and received unblinded interim analyses.”

MethodsFind in source

The investigational product (LPG cookstove) is described as unvented with ≥2 burners meeting local safety standards. The pulse oximeter (Masimo Rad-G) and ultrasound (Sonosite Edge) are identified with manufacturer and model. Software tools (e.g., for statistical analysis) are not explicitly named with versions, but the analysis methods (Poisson GEE, Cox) are standard. Reagents/antibodies/cell lines are not applicable.

Sub-criteria

mycoplasma testingN/A

reagents identifiedADEQUATE

organisms identifiedN/A

antibodies identifiedN/A

cell line authenticationN/A

software tools identifiedINADEQUATE

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 85% conf

Key resources are adequately identified, including the intervention (LPG stoves) and measurement devices.

Evidence

“Unvented LPG cookstoves all had ≥2 burners and met local safety standards.”

MethodsFind in source

“facility study staff applied a Masimo Rad-G ® pulse oximeter (Masimo, Irvine, CA, USA)”

MethodsFind in source

PASSReviewer 2· 90% conf

Key resources are adequately identified: the LPG cookstoves, pulse oximeter (Masimo Rad-G), and ultrasound (Sonosite Edge) are named with manufacturer and model. Software tools are not explicitly versioned, but the statistical methods are standard.

Evidence

“Unvented LPG cookstoves all had ≥2 burners and met local safety standards.”

MethodsFind in source

paraphrase[Methods, Outcome]

“To measure SpO2, facility study staff applied a Masimo Rad-G ® pulse oximeter (Masimo, Irvine, CA, USA) ... Chest imaging was by ultrasound (Sonosite Edge, Bothell, WA, USA)”

The primary analysis uses Poisson regression with GEE, and the test is named. Exact p-values are reported (p=0.81). Effect sizes are reported with 98.75% CIs (adjusted for multiplicity). Statistical software is not explicitly named, but the analysis was conducted by two independent teams. Data presentation includes per-group n, incidence rates, and CIs. Mathematical plausibility checks are not applicable for large-N continuous outcomes.

Sub-criteria

tests namedADEQUATE

exact p valuesADEQUATE

effect sizes ciADEQUATE

data presentationADEQUATE

software identifiedINADEQUATE

assumptions verifiedADEQUATE

mathematical plausibilityN/A

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

Statistical analysis is rigorous with named tests, effect sizes with CIs, and appropriate handling of multiplicity.

Evidence

“We used Poisson regressions with generalized estimating equations (GEE) to model the incidence of all episodes of severe pneumonia using infant days at risk as the denominator to derive incidence rate ratios (IRRs).”

Statistical analysisFind in source

“incidence rate ratio (98.7% CI) 0.96 (0.64, 1.44; p=0.81)”

ResultsFind in source

PASSReviewer 2· 95% conf

Statistical analysis is rigorous: tests are named (Poisson GEE, Cox), the primary analysis is ITT, exact p-values are reported, effect sizes with CIs are provided, and software is implied. Data presentation includes per-group n and CIs.

Evidence

Statistical analysisFind in source

“incidence rate ratio (98.7% CI) 0.96 (0.64, 1.44; p=0.81)”

ResultsFind in source

The paper states 'A data sharing statement provided by the authors is available with the full text of this article at NEJM.org.' This is a vague statement; the actual mechanism is not described in the paper. No repository deposit, accession numbers, or code sharing are mentioned. For a clinical trial, managed access is acceptable, but the statement here is inadequate as it does not describe the conditions or platform.

Sub-criteria

code sharingNOT REPORTED

accession numbersNOT REPORTED

repository depositNOT REPORTED

data availability statementINADEQUATE

Per reviewer (2) — the votes behind the verdict

WARNReviewer 1· 80% conf

Data availability is mentioned but not concrete; no repository or accession numbers are provided.

Evidence

paraphrase[Supplementary Material 1, Acknowledgements]

“A data sharing statement provided by the authors is available with the full text of this article at NEJM.org (http://NEJM.org).”

WARNReviewer 2· 85% conf

A data sharing statement is mentioned as available at NEJM.org, but the specific mechanism is not described in the paper text. No repository deposit or accession numbers are provided. Code sharing is not mentioned.

Evidence

paraphrase[End of main text, before Supplementary Material]

“A data sharing statement provided by the authors is available with the full text of this article at NEJM.org.”

Methods are comprehensive. Trial registration is provided (NCT029446282). A reporting guideline is not explicitly referenced, but the paper follows standard clinical trial reporting. All outcomes are reported, including null results. Limitations are discussed in detail. Conclusions are proportional to the evidence. Funding sources and COI are disclosed.

Sub-criteria

funding coiADEQUATE

trial registrationADEQUATE

reporting guidelineNOT REPORTED

methods completenessADEQUATE

all outcomes reportedADEQUATE

limitations discussedADEQUATE

conclusions proportionalADEQUATE

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

Reporting is transparent with trial registration, limitations discussed, and conclusions proportional.

Evidence

“NCT029446282 (https://clinicaltrials.gov/ct2/show/NCT029446282)”

AcknowledgementsFind in source

paraphrase[Discussion, paragraph 4]

“Limitations of our study should be noted. Incomplete assessments at facility visits may have led to missed cases, although this is unlikely to have impacted our results because missingness among screened children was low.”

PASSReviewer 2· 95% conf

Reporting is transparent: methods are detailed, the trial is registered (NCT029446282), limitations are discussed, conclusions are proportional, and funding/COI are disclosed. A reporting guideline is not explicitly mentioned, but the paper follows CONSORT-like structure.

Evidence

“NCT029446282 (https://clinicaltrials.gov/ct2/show/NCT029446282)”

Supplementary materialFind in source

paraphrase[Discussion, paragraph 4]

“Limitations of our study should be noted. Incomplete assessments at facility visits may have led to missed cases...”

paraphrase[Support Statement and Footnotes]

“The HAPIN trial is funded by the U.S. National Institutes of Health (cooperative agreement 1UM1HL134590) in collaboration with the Bill & Melinda Gates Foundation [OPP1131279]. Disclosure forms provided by the authors are available with the full text of this article at NEJM.org.”

No trial/study registration detected. Reporting guideline cited: CONSORT.

Reporting guidelines: CONSORT

Broken references and links

1 finding · worst low

References checked against Crossref, OpenAlex and Retraction Watch for retractions and resolvability, plus declared data and code links probed for whether they resolve to content matching the paper.

References not resolvable to a published paperRecomputed

Checked 40 references by DOI: 1 verified — 1 DOI unresolved, 38 no DOI (shown, not verified).

UNRESOLVED10.1016/s1473-3099(19
Tracking SDG7 The Energy Progress Report 2022
Cited DOI does not resolve to any Crossref record.
NO DOI
A cluster randomised trial of cookstove interventions to improve infant health in Ghana
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
E!ect of an improved biomass stove on acute lower respiratory infections in young children in rural Nepal: a cluster-randomised, step-wedge trial
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
A cleaner burning biomass-fuelled cookstove intervention to prevent pneumonia in children under 5 years old in rural Malawi (the Cooking and Pneumonia Study): a cluster randomised controlled trial
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Effect of reduction in household air pollution on childhood pneumonia in Guatemala (RESPIRE): a randomised controlled trial
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Design and Rationale of the HAPIN Study: A Multicountry Randomized Controlled Trial to Assess the Effect of Liquefied Petroleum Gas Stove and Continuous Fuel Distribution
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Liquefied Petroleum Gas or Biomass for Cooking and Effects on Birth Weight
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Designing a comprehensive behaviour change intervention to promote and monitor exclusive use of liquefied petroleum gas stoves for the Household Air Pollution Intervention Network (HAPIN) trial
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Air Pollutant Exposure and Stove Use Assessment Methods for the Household Air Pollution Intervention Network (HAPIN) Trial
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Compensating control participants when the intervention is of significant value: experience in Guatemala, India, Peru and Rwanda
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Fidelity and adherence to a liquefied petroleum gas stove and fuel intervention: the multi-country Household Air Pollution Intervention Network (HAPIN) trial
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Post-birth exposure contrasts for children during the Household Air Pollution Intervention Network randomized controlled trial
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Resources and Geographic Access to Care for Severe Pediatric Pneumonia in Four Resource-limited Settings
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Design and conduct of facility-based surveillance for severe childhood pneumonia in the Household Air Pollution Intervention Network (HAPIN) trial
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Challenges in the diagnosis of paediatric pneumonia in intervention field trials: recommendations from a pneumonia field trial working group
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Effects of high altitude on respiratory rate and oxygen saturation reference values in healthy infants and children younger than 2 years in four countries: a cross-sectional study
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Risk and accuracy of outpatient-identified hypoxaemia for death among suspected child pneumonia cases in rural Bangladesh: a multifacility prospective cohort study
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Lung Ultrasound Protocol and Quality Control of Image Interpretation Using an Adjudication Panel in the Household Air Pollution Intervention Network (HAPIN) Trial
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Lung ultrasound compared to chest X-ray for diagnosis of pediatric pneumonia: A meta-analysis
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Training physicians in India to interpret pediatric chest radiographs according to World Health Organization research methodology
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Prospective study of one million deaths in India: rationale, design, and validation results
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Integrated Management of Childhood Illness: Chart Booklet
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Pocketbook of Hospital care for children: Guidelines for the management of common childhood illnesses, Second Edition
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Impact of the introduction of pneumococcal conjugate vaccination on pneumonia in The Gambia: population-based surveillance and case-control studies
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Multi-center surveillance for pneumonia & meningitis among children (<2 yr) for Hib vaccine probe trial preparation in India
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Burden of Severe Pneumonia, Pneumococcal Pneumonia and Pneumonia Deaths in Indian States: Modelling Based Estimates
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
A prospective three-year cohort study of the epidemiology and virology of acute respiratory infections of children in rural India
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Fidelity and Adherence to a Liquefied Petroleum Gas Stove and Fuel Intervention during Gestation: The Multi-Country Household Air Pollution Intervention Network (HAPIN) Randomized Controlled Trial
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Exposure Contrasts of Pregnant Women during the Household Air Pollution Intervention Network Randomized Controlled Trial
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Effects of cooking with liquefied petroleum gas or biomass on infant stunting
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Association between household air pollution and nasopharyngeal pneumococcal carriage in Malawian infants (MSCAPE): a nested, prospective, observational study
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Examining the relationship between household air pollution and infant microbial nasal carriage in a Ghanaian cohort
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Streptococcus pneumoniae colonisation: the key to pneumococcal disease
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Causes of severe pneumonia requiring hospital admission in children without HIV infection from Africa and Asia: the PERCH multi-country case-control study
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Decreased Influenza Activity During the COVID-19 Pandemic - United States, Australia, Chile, and South Africa, 2020
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Decline of influenza and respiratory syncytial virus detection in facility-based surveillance during the COVID-19 pandemic, South Africa, January to October 2020
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
WHO global air quality guidelines: particulate matter (PM2.5 and PM10), ozone, nitrogen dioxide, sulfur dioxide and carbon monoxide
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Nitrogen dioxide exposures from LPG stoves in a cleaner-cooking intervention trial
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
NO DOI
Short-term effects of PM10 and NO2 on respiratory health among children with asthma or asthma-like symptoms: a systematic review and meta-analysis
No DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).

Copyediting

3 minor

Wording, consistency and formatting errors that need correcting before submission.

No major wording or formatting errors. 3 minor suggestions below.

3 copyedit issues flagged: mostly consistency, clarity.

MINORconsistencyAbstract, Results
“incidence rate ratio 0.96 [98.75% CI, 0.64, 1.44; p=0.81]”
→ Use consistent bracket style: (98.75% CI, 0.64 to 1.44; p=0.81)
Bracket style differs from main text.
MINORclarityMethods, Outcome
“The primary case definition was adapted from World Health Organization (WHO) guidelines based on external expert input.”
→ Clarify that the definition was adapted based on external expert input.
Slightly awkward phrasing.
MINORconsistencyResults, Primary outcome
“The severe pneumonia incidence rate in the first year of life was 5.67 (95% CI 4.45, 7.07) per 100 child-years in the LPG group and 6.06 (95% CI 4.81, 7.62) per 100 child-years in the control group”
→ The CI for the intervention group is given as 4.45, 7.07 in the text but as 4.55, 7.07 in the abstract. Please verify and correct for consistency.
Abstract states 4.55, results text states 4.45.

Kaimen Rigor Action ItemsFinal pass before journal submission

The published work is robust and generally trustworthy, with strong design and reporting. An informed reader should weigh the minor reporting gaps (data availability statement, software identification, reporting guideline) and the copyedit inconsistency in the CI value, but none of these undermine the core findings. No erratum is warranted for the rigor dimensions, though the CI discrepancy should be corrected.

1.
CRITICALstatistics
Correct or explain the statistically impossible value: PERCENT: 58.9% does not match the reported count 904/1515
Demonstrable critical failure — blocks the verdict from passing.
2.
CRITICALstatistics
Correct or explain the statistically impossible value: PERCENT: 53.8% does not match the reported count 820/1503
Demonstrable critical failure — blocks the verdict from passing.
3.
HIGHdata code
Replace the vague data sharing statement in the main text with a concrete description of the access mechanism (e.g., a named repository or data access committee with conditions) and provide a persistent identifier or accession number.
The current statement merely refers to a separate statement at NEJM.org, which is inadequate for a data-driven clinical trial and undermines reproducibility.
4.
HIGHstatistics
Name the statistical software and version used for all analyses in the Methods section (e.g., R version 4.x, SAS 9.4).
Both reviewers flagged the absence of software identification, which is a standard reporting requirement for reproducibility.
5.
HIGHreporting
Explicitly state adherence to the CONSORT reporting guideline in the Methods section.
The paper follows CONSORT-like structure but does not name the guideline, which is a transparency gap for an RCT.
6.
HIGHethics
Add a statement of compliance with the Declaration of Helsinki or ICH-GCP in the ethics/oversight section.
Reviewer 2 noted that regulatory compliance is not explicitly named; adding this strengthens the ethics reporting.
7.
HIGHcopyedit
Correct the inconsistency in the 95% CI for the intervention group incidence rate: the abstract states 4.55 while the results text states 4.45; verify and align both to the correct value.
The copyedit pass flagged this numerical discrepancy, which could confuse readers and undermine trust in the reported data.
8.
MEDIUMcopyedit
Standardize the bracket style for confidence intervals in the Abstract (e.g., use parentheses consistently: (98.75% CI, 0.64 to 1.44; p=0.81)).
The copyedit pass noted inconsistent bracket style between the abstract and main text.
9.
MEDIUMcopyedit
Rephrase the sentence in Methods, Outcome about the primary case definition to improve clarity: 'The primary case definition was adapted from World Health Organization (WHO) guidelines based on external expert input.'
The copyedit pass flagged the phrasing as slightly awkward; clarifying improves readability.
10.
MEDIUMdata code
If possible, deposit de-identified aggregate data in a public repository with a DOI to enhance transparency.
A concrete data deposit would strengthen the data availability and allow independent verification.
11.
MEDIUMdata code
Share custom analysis code in a public repository (e.g., GitHub, Zenodo) with a persistent identifier.
Code sharing is not mentioned; providing it would improve reproducibility.
12.
LOWother
Verify the reference 'Tracking SDG7 The Energy Progress Report 2022' (DOI 10.1016/s1473-3099(19) — the DOI appears incomplete) and correct or replace it if it cannot be found in any registry.
The citation verification component flagged this reference as not found in the registry, which may indicate a fabrication or an incomplete DOI; it should be checked.

Full text (33,527 chars)Analyzed: Aug 16, 2026

RigorReviewer 1

RigorReviewer 2

RigorPre-Submission Reviewer

CopyeditAgent Scribe

CitationsCitation Integrity

StatisticsStatistics Consistency

PreregistrationDeterministic check· no model (rule-based)

The star rating is the report’s one-glance summary. Every paper starts at 5★ and loses stars for the concrete problems the review finds — so a rating is never a vague average, it’s a running total you can read line by line under “How this rating was calculated.”

How stars are deducted

Reporting — 8 dimensionseach dimension that fully fails−½★
each dimension partially met−¼★
Statistics · Integrity · Claimseach serious problem−1★
each medium problem−½★
Citationseach retracted or unverifiable reference−¼★
Copyeditonly when the manuscript needs a full edit−½★

The rating never drops below 1★, and a demonstrable critical failure (an impossible statistic, a proven ethics violation) caps it at 1★ on its own — so the stars can never look healthy when the verdict is CRITICAL.

The rating draws on a panel of agents. Three independent Kaimen Rigor reviewers grade the eight dimensions below across several independent passes (the shown verdict is their majority vote — steadier than any single run), isolate the paper’s major claims and check its own evidence backs them, and flag integrity concerns. Alongside them, a citation agent resolves every reference against Crossref, OpenAlex, and Retraction Watch; a statistics agent recomputes reported tests; and rule-based checks verify that declared data/code links actually resolve. Full text is required — an abstract-only submission is not analyzed.

The eight reporting dimensions

Scientific PremisePrior work, rationale, and how it addresses gaps.

Study Design & RigorRandomization, blinding, power, controls, replication.

Biological VariablesSex, age, species/strain, housing, demographics.

Ethical ApprovalsIRB/IACUC approval, informed consent, regulatory compliance.

Key ResourcesAntibodies, cell lines, organisms, software — identified with persistent IDs.

Statistical ReportingNamed tests, exact p-values, effect sizes, plausible summary stats.

Data & Code AvailabilityAvailability statements, repositories, accession numbers, shared code.

Reporting TransparencyMethods, registration, guidelines, outcomes, limitations, funding/COI.

Graded against NIH, MDAR, ARRIVE 2.0, CONSORT, EQUATOR, and RRID guidelines. A dimension that doesn’t apply to the study type is skipped, never penalized.

This Kaimen Rigor review is model-assisted and is not a substitute for formal expert review. It complements human evaluation by surfacing potential methodological concerns — verify each finding against the source.

Liquefied Petroleum Gas or Biomass Cooking and Severe Infant Pneumonia.

DOI

10.1056/NEJMoa2305681

Record issued

2026-08-16

Engine

7.39.0

Exported

2026-09-21