Evidence map›Paper›PMID 38826636›Full record

ArticlePublic health in practice (Oxford, England)2024

Impact of a nationwide school policy on body mass index in Danish school children: An interrupted time series analysis.

Natascha H Pedersen, Anders Grøntved, Niels C Møller, Birgit Debrabant, Kristian T Larsen, Jan C Brønd, Jens Troelsen, Søren Brage, Jacob V B Hjelmborg, Niels Wedderkopp and 6 more

Abstract read
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In one paragraph

Article in Public health in practice (Oxford, England), 2024. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

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.

2 · The registry

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.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Article
  2. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

16 authors.

Natascha H PedersenCentre of Research in Childhood Health, Research Unit for Exercise Epidemiology, Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
Anders GrøntvedCentre of Research in Childhood Health, Research Unit for Exercise Epidemiology, Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
Niels C MøllerCentre of Research in Childhood Health, Research Unit for Exercise Epidemiology, Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
Birgit DebrabantData Science and Statistics, Department of Mathematics and Computer Science, University of Southern Denmark, Odense, Denmark.
Kristian T LarsenCentre of Research in Childhood Health, Research Unit for Exercise Epidemiology, Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
Jan C BrøndCentre of Research in Childhood Health, Research Unit for Exercise Epidemiology, Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
Jens TroelsenResearch Unit for Active Living, Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
Søren BrageCentre of Research in Childhood Health, Research Unit for Exercise Epidemiology, Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
Jacob V B HjelmborgEpidemiology, Biostatistics and Biodemography, University of Southern Denmark, Odense, Denmark.
Niels WedderkoppCentre of Research in Childhood Health, Research Unit for Exercise Epidemiology, Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
Lars B ChristiansenResearch Unit for Active Living, Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
Sofie R MortensenCentre of Research in Childhood Health, Research Unit for Exercise Epidemiology, Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
Heidi K EgebækCentre of Research in Childhood Health, Research Unit for Exercise Epidemiology, Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
Mette ToftagerResearch Unit for Active Living, Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
Malene S HeidemannHans Christian Andersen Children's Hospital, Odense University Hospital, Odense, Denmark.
Peter L KristensenCentre of Research in Childhood Health, Research Unit for Exercise Epidemiology, Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Objectives: A new school policy mandating 45 min physical activity daily during school was introduced in Denmark in 2014. We aimed to evaluate the effect of this policy on BMI in school-aged children. It was hypothesized that the school policy would decrease BMI, especially in the obese fraction of the population (90th percentile BMI). Study design: This register-based study was conducted as a natural experiment. Methods: Analyses were based on data from The National Child Health Register that contains nationwide data on height and weight from mandatory preventive health examinations completed by school nurses or medical doctors during pre-preparatory classes (0th-3rd grade) and lower secondary education (7th-9th grade). A total of 401,517 children were included in the analyses with annual repeated cross-sectional data covering the period from 2012 to 2018. The effect of the school policy was evaluated using an interrupted time series approach comparing pre- and post-policy slopes in BMI, stratified by sex and age-group. Results: In boys, no significant differences were observed in mean BMI slopes from pre-to post-policy in either age-group. In girls, post-policy slopes were significantly higher compared to pre-policy in both age-groups (0th-3rd grade: β:0·034 kg/m2, 95%-CI: (0·024; 0·043), p-value: <0·001; 7th-9th grade: β:0·066 kg/m2, 95%-CI: (0·028; 0·103), p-value: 0·001). No significant differences in slopes were observed in BMI at the 90th percentile from pre-to post-policy for both sexes and across both age-groups. Adjustment for leisure-time physical activity as a potential time-varying confounder did not alter the findings. Conclusions: In conclusion, we did not detect a significant decrease in BMI levels among school-aged children following the introduction of a nationwide school policy specifying daily physical activity in school. If anything, a small positive change in BMI was observed in girls. More research is needed to understand whether structural changes similar to this requirement are able to prevent overweight and obesity in children and adolescents.

Identifiers

PMID38826636
PMCPMC11141446

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.