ArticleBMJ open2025
Urinary cotinine cut-off concentrations in children under 5 years for assessing environmental tobacco smoke exposure: a systematic review and meta-analysis protocol.
Article in BMJ open, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
2 citing papers in PubMed.
- A Meta-Analysis of Urinary Cotinine Cut-Off Concentrations in Children Under Five Years for Assessing Environmental Tobacco Smoke Exposure.Tobacco use insights · 2026Review
- Biomarker-based assessment of tobacco smoke exposure in Saudi females via analysis of urinary cotinine level.PloS one · 2026Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
introductionEnvironmental tobacco smoke (ETS) is generally known as secondhand smoke. Assessing the magnitude of children's exposure to ETS from early infancy is essential for public health and research endeavours. Urinary cotinine is now widely recognised as the primary indicator for assessing exposure to ETS across all age groups. This systematic review and meta-analysis aim to synthesise all the published evidence on the urinary cotinine cut-off concentrations used to categorise children under 5 years as being exposed to ETS. METHODS AND ANALYSIS: We will conduct a systematic review according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses. A comprehensive search will be conducted from various databases including PubMed, EMBASE, Scopus and Cochrane Library. This search will be performed from the earliest published articles up to the latest available studies until February 2025. We will include all the experimental and observational studies, such as cohort, case-control and cross-sectional, that measure urinary cotinine concentrations in children under 5 years old. Data extraction will be conducted using a standardised data extraction form, and the study quality will be evaluated according to the guidelines specified by the Newcastle-Ottawa Scale. The extracted data will be pooled and combined for meta-analysis. Two reviewers will independently screen, select and assess the quality of the included study. The result will be tabulated in a table of characteristics of the included study, which consists of the cut-off cotinine concentrations, analytical technique, method referred, study design, study area and respondents' characteristics. ETHICS AND DISSEMINATION: Ethics approval is not required as this is a review of collected published data. Findings will be disseminated in peer-reviewed publications and conference presentations, as well as with key stakeholders, health policymakers and healthcare professionals. PROSPERO REGISTRATION NUMBER: CRD42024556969.
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Registered trials
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