Evidence map›Paper›PMID 19290678›Full record

SynthesisSports medicine (Auckland, N.Z.)2009

Annual age-grouping and athlete development: a meta-analytical review of relative age effects in sport.

Stephen Cobley, Joseph Baker, Nick Wattie, Jim McKenna

Abstract readMeta-AnalysisReview
PubMed Publisher
In one paragraph

Synthesis in Sports medicine (Auckland, N.Z.), 2009. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 243 papers, 9 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
243citing papers in PubMed, 9 pooled it
–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

243 citing papers in PubMed, 9 syntheses or guidelines pooled it.

  1. Pooled it
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  7. Prevalence and Impact of the Relative Age Effect on Competition Performance in Swimming: A Systematic Review.International journal of environmental research and public health · 2021
    Pooled it
  8. Impact of the Relative Age Effect on Competition Performance in Basketball: A Qualitative Systematic Review.International journal of environmental research and public health · 2020
    Pooled it
  9. Pooled it
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  14. Skeletal Age Evaluation with BAUSportJournal of functional morphology and kinesiology · 2026
    Article
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183 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

4 authors.

Stephen CobleyCarnegie Research Institute, Leeds Metropolitan University, Leeds, West Yorkshire, UK. s.cobley@leedsmet.ac.uk
Joseph Baker
Nick Wattie
Jim McKenna

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Annual age-grouping is a common organizational strategy in sport. However, such a strategy appears to promote relative age effects (RAEs). RAEs refer both to the immediate participation and long-term attainment constraints in sport, occurring as a result of chronological age and associated physical (e.g. height) differences as well as selection practices in annual age-grouped cohorts. This article represents the first meta-analytical review of RAEs, aimed to collectively determine (i) the overall prevalence and strength of RAEs across and within sports, and (ii) identify moderator variables. A total of 38 studies, spanning 1984-2007, containing 253 independent samples across 14 sports and 16 countries were re-examined and included in a single analysis using odds ratios and random effects procedures for combining study estimates. Overall results identified consistent prevalence of RAEs, but with small effect sizes. Effect size increased linearly with relative age differences. Follow-up analyses identified age category, skill level and sport context as moderators of RAE magnitude. Sports context involving adolescent (aged 15-18 years) males, at the representative (i.e. regional and national) level in highly popular sports appear most at risk to RAE inequalities. Researchers need to understand the mechanisms by which RAEs magnify and subside, as well as confirm whether RAEs exist in female and more culturally diverse contexts. To reduce and eliminate this social inequality from influencing athletes' experiences, especially within developmental periods, direct policy, organizational and practitioner intervention is required.

Indexed as

AdolescentAdolescent DevelopmentAge DistributionBody HeightBody WeightChildChild DevelopmentHumansOdds RatioSportsYoung Adult

Identifiers

PMID19290678

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

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.