Data sharing—trialists' plans at registration, attitudes, barriers and facilitators: A cohort study and cross‐sectional survey
Open accessAbstract
Data unavailability impedes research transparency and is a major problem for individual participant data (IPD) meta‐analyses as it reduces statistical power, increases risk of bias, and may even preclude completion. The primary objectives of this study were to determine IPD sharing plans reported in recently registered clinical trial registration records, how data sharing commitment relates to clinical trial characteristics, and principal investigators' attitudes, motivations and barriers to data sharing. The secondary objective was to derive recommendations to overcome identified barriers to data sharing. This was a retrospective cohort study of all interventional trials registered on the Australian New Zealand Clinical Trials Registry (ANZCTR) from 1 December 2018 to 30 November 2019, and an online cross‐sectional survey of their principal investigators. In the cohort study of all clinical trials registered on the ANZCTR in the study period (n = 1517), commitment to share data was low (22%, 329/1517). In the cross‐sectional survey (n = 281, 23% response rate), principal investigators showed strong support for the concept of data sharing (77%, 216/281) but a substantially lower intention to actually share data from their clinical trials (40%, 111/281). Major barriers to data sharing included lacking informed consent to share data, protecting participant confidentiality and preventing misinterpretation of data or misleading secondary analyses. There is a gap between high in‐principle support for data sharing, and low in‐practice intention from investigators to share data from their own clinical trials. Multiple pathways exist to bridge this gap by addressing the identified barriers to data sharing.
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One review of eight published meta-epidemiological studies reported that trials with a high risk of influence from industry funders reported 12% (odds ratio) more beneficial effects (95% CI 3% to 19%), on average, than comparable trials without high risk of funder influence.
“One review of eight published meta-epidemiological studies reported that trials with a high risk of influence from industry funders, such as on trial design, conduct, and analysis, reported 12% (odds ratio) more beneficial effects (95% confidence interval (CI) 3% to 19%), on average, than comparable trials without high risk of funder influence.52”
From SPIRIT 2025 explanation and elaboration: updated guideline for protocols of randomised trials (2025) · cites this paper as [52]
Industry funded trials with greater funder involvement tend to report more favourable results than comparable trials without such involvement.
“Industry funded trials with greater funder involvement tend to report more favourable results (ie, larger estimates of intervention effects) than comparable trials without such involvement.”
From SPIRIT 2025 explanation and elaboration: updated guideline for protocols of randomised trials (2025) · cites this paper as [52]
One review of eight published meta-epidemiological studies found that on average odds ratios from industry funded trials did not differ significantly from non-industry funded trials; however, in the subset of trials with a high risk of industry funder influence, the difference was 12% (95% CI 3% to 19%).
“One review of eight published meta-epidemiological studies reported that, on average, odds ratios from industry funded trials did not differ significantly from those of non-industry funded trials. However, in the subset of trials with a high risk of industry funder influence (eg, on trial design, conduct, and analysis), the difference was 12% (95% CI 3% to 19%).52”
From SPIRIT 2025 explanation and elaboration: updated guideline for protocols of randomised trials (2025) · cites this paper as [52]
Industry funded trials might report more favourable results than comparable trials funded by other sources, although the evidence is less certain.
“Industry funded trials might also report more favourable results (ie, estimates of intervention effects) than comparable trials that are funded by other sources, although the evidence is less certain.”
From SPIRIT 2025 explanation and elaboration: updated guideline for protocols of randomised trials (2025) · cites this paper as [52]
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- Authors
- Tan, A. C., Askie, L. M., Hunter, K. E., Barba, A., Simes, R. J., & Seidler, A. L.
- Affiliations
- The University of Sydney (AU)
- Corresponding author
- Seidler, Anna Lene
- ORCID
- Venue
- Research Synthesis Methods
- Publisher
- Wiley
- Published
- 2021-06-15
- Volume
- 12
- Issue
- 5
- Pages
- 641-657
- ISSN
- 1759-2879 (ISSN-L)
- 1759-2887
- OpenAlex
- W3165880742
- Cited by
- 48
- References
- 47
- Citations by year
- 2026: 7 · 2025: 11 · 2024: 15 · 2023: 7 · 2022: 7 · 2021: 1
- FWCI
- 6.77
- Type
- journal article
- Language
- en
- Open access
- green
- hdl.handle.net
- Locations
- Research Synthesis Methods (publishedVersion)
- PubMed (publishedVersion)
- The Sydney eScholarship Repository (The University of Sydney) (submittedVersion, cc-by)
- Topics
- Physical Sciences › Computer Science › Information Systems › Research Data Management Practices
- Social Sciences › Decision Sciences › Statistics, Probability and Uncertainty › Meta-analysis and systematic reviews
- Social Sciences › Decision Sciences › Information Systems and Management › Academic Publishing and Open Access
- Keywords
- data sharing, individual patient data, clinical trial registration, barriers to data sharing, data availability, participant confidentiality, informed consent, research transparency
- MeSH terms
- Attitude, Australia, Clinical Trials as Topic, Cross-Sectional Studies, Humans, Retrospective Studies, Cohort Studies, Information Dissemination
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