Evidence map›Paper›PMID 42071174›Full record

ArticleClinical and translational science2026

A Pilot Study to Explore Length and Readability Characteristics of Subject Information Sheets/Informed Consent Forms of Clinical Trial Applications in the EU.

Sophie Brunner Ziegler, Fabian Eibensteiner, Nina Reumann, Martin Brunner, Franz König, Eva Maria Zebedin Brandl

Abstract read
In one paragraph

Article in Clinical and translational science, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing 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

0 citing papers in PubMed.

No citing paper in PubMed yet.

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

6 authors.

Sophie Brunner ZieglerDivision of Angiology, Department of Internal Medicine II, Medical University of Vienna, Vienna, Austria.ORCID 0000-0001-7825-1254
Fabian EibensteinerCenter for Medical Data Science, Medical University of Vienna, Vienna, Austria.ORCID 0000-0001-5012-3082
Nina ReumannInstitute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria.
Martin BrunnerDepartment of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.
Franz KönigCenter for Medical Data Science, Medical University of Vienna, Vienna, Austria.ORCID 0000-0002-6893-3304
Eva Maria Zebedin BrandlInstitute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria.ORCID 0000-0001-8479-0158

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

The Clinical Trials Information System (CTIS) enables a central joint registration of clinical trials in the EU and provides public access to key trial documents including informed consent documents. The increasing complexity and length of subject information sheets and informed consent forms (SIS/ICFs) can impact participant comprehension and willingness to enroll in a trial. This pilot study aimed to analyze the characteristics of actual SIS/ICFs from a sample of approved CTIS submissions, with a focus on Phase III trials. We consulted the CTIS public database to retrieve authorized Phase III trials. The final dataset comprised 67 drug trials submitted between January 1, 2023, and November 16, 2023. SIS/ICF page and word count, and readability scores were compared across countries, sponsorship, and other trial-related characteristics. Exploratory analyses assessed document structure and page space utilization. The median SIS/ICF length was 16 pages (IQR 11-23) and 5746 words (IQR 3508-8626), with substantial variability. Industry-sponsored trials had significantly longer SIS/ICFs than academic trials (mean difference + 8.1 pages, p < 0.01). German SIS/ICFs were on average 4.4 pages longer than Austrian SIS/ICFs (p = 0.018). Exploratory analyses suggested that formatting choices, repetition, and expanded data protection sections contributed more to length differences than content allocation or readability, thus indicating that the main drivers of SIS/ICF length are modifiable in nature. These findings underscore the need for further research into the factors influencing document length, their implications for trial participants and how a further harmonization throughout the EU can be achieved for country-specific documents.

Indexed as

Clinical Trials as TopicClinical Trials, Phase III as TopicComprehensionConsent FormsInformed ConsentEuropean UnionHumansPilot Projects

Identifiers

PMID42071174
PMCPMC13136066

What Socratic holds

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LicenceCC BY-NC
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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 Socratic graph.