Evidence map›Paper›PMID 36602999›Full record

ArticlePloS one2023

Publication bias in trials registered in the Australian New Zealand Clinical Trials Registry: Is it a problem? A cross-sectional study.

Marian Showell, Sam Buckman, Slavica Berber, Nada Ata Allah, Ben Patterson, Samantha Cole, Cynthia Farquhar, Vanessa Jordan

Abstract read
PubMed Publisher
In one paragraph

Article in PloS one, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 9 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
9citing papers in PubMed, 1 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

9 citing papers in PubMed, 1 synthesis or guideline pooled it.

  1. Time to publication for results of clinical trials.The Cochrane database of systematic reviews · 2024
    Pooled it
  2. Article
  3. Article
  4. Determinants of publication likelihood and timeliness for clinical studies.Journal of clinical and translational science · 2026
    Article
  5. Landscape analysis of oncology nutrition research among patients being treated for cancer.Supportive care in cancer : official journal of the Multinational Association of Supportive Care in Cancer · 2025
    Article
  6. Review
  7. Review
  8. Review
  9. 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

8 authors.

Marian ShowellDepartment of Obstetrics and Gynecology, University of Auckland, Auckland, New Zealand.ORCID 0000-0002-1227-4303
Sam BuckmanDepartment of Obstetrics and Gynecology, University of Auckland, Auckland, New Zealand.
Slavica BerberEvidence Integration, NHMRC Clinical Trials Centre, The University of Sydney, Camperdown, Australia.
Nada Ata AllahFaculty of Medicine, Department of Obstetrics & Gynecology, Aleppo University Hospital, University of Aleppo, Aleppo, Syria.
Ben PattersonDepartment of Medical Microbiology, St George's Hospital, London, United Kingdom.
Samantha ColeDepartment of Obstetrics and Gynecology, University of Auckland, Auckland, New Zealand.
Cynthia FarquharDepartment of Obstetrics and Gynecology, University of Auckland, Auckland, New Zealand.
Vanessa JordanDepartment of Obstetrics and Gynecology, University of Auckland, Auckland, New Zealand.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundTimely publication of clinical trials is critical to ensure the dissemination and implementation of high-quality healthcare evidence. This study investigates the publication rate and time to publication of randomized controlled trials (RCTs) registered in the Australian New Zealand Clinical Trials Registry (ANZCTR). MATERIALS AND

methodsWe conducted a cross-sectional study of RCTs registered with the ANZCTR in 2007, 2009, and 2011. Multiple bibliographic databases were searched until October 2021 to identify trial publications. We then calculated publication rates, proportions, and the time to publish calculated from the date of first participation enrolment to publication date.

resultsOf 1,970 trial registrations, 541 (27%) remained unpublished 10 to 14 years later, and the proportion of trials published decreased by 7% from 2007 to 2011. The average time to publish was 4.63 years. The prospective trial registration rate for 2007, 2009 and 2011 was 48% (952 trials) and over this time there was an increase of 19% (280 prospective trials). Trials funded by non-Industry organizations were more likely to be published (74%, 1204/1625 trials) than the industry-funded trials (61%, 224/345 trials). Larger trials with at least 1000 participants were published at a rate of 88% (85/97 trials) and on average took 5.4 years to be published. Smaller trials with less than 100 participants were published at a lower rate with 67% (687/1024 trials) published and these trials took 4.31 years on average to publish.

conclusionsJust over a quarter of all trials on the ANZCTR for 2007, 2009, and 2011 remain unpublished over a decade later. The average time to publication of nearly five years may reflect the larger trials which will have taken longer to recruit participants. Over half of study sample trials were retrospectively registered, but prospective registration improved over time, highlighting the role of mandating trial registration.

Indexed as

Research DesignAustraliaCross-Sectional StudiesHumansNew ZealandPublication BiasRandomized Controlled Trials as TopicRegistries

Identifiers

PMID36602999

What OpenQuestion holds

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LicenceCC BY
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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.