Good Lay Summary Practice (GLSP) refers to recommendations from the European Commission for preparing lay summaries of clinical trial results. The Guidance specifies how study results can be prepared in accordance with Regulation (EU) No 536/2014 in language understandable to non-expert readers. It structures the work into planning, preparation, translation, and dissemination.
Target Audience and Occasion for the Guidance
The recommendations refer to the lay summary of results for a clinical trial of medicinal products for human use within the European legal framework. Articles 37 and Annex V of Regulation (EU) No 536/2014 form the context for the results summary. The European Commission published the Good Lay Summary Practice Guidance through its Directorate-General for Health and Food Safety, within the framework of the EudraLex guidelines for clinical trials.
A uniform German legal term for “lay summary” has not been established. “Laienverständliche Ergebniszusammenfassung” (lay-understandable results summary) clearly describes in German what it entails: not a scientific abstract for professionals, but an independent explanation of the study and its results for the general public, and especially for study participants.
Planning, Preparation, Translation, and Dissemination
GLSP does not treat the summary as a retrospective linguistic abridgement of the Clinical Study Report. Even during planning, target groups, responsibilities, data sources, and the trial pathway must be considered. During preparation, the focus is on clear language, a logical sequence of topics, and the explanation of medical terms. The statement must neither conceal risks nor overstate the benefits of an intervention.
For translations, content and comprehensibility must be maintained in every intended language; a literal transfer of complex technical terminology is not sufficient. Dissemination follows the approval of the summary and concerns its provision via the designated European transparency channels. GLSP links these work steps to ensure that the technical documents and the lay version do not diverge.
Distinction: Guideline and Legal Obligation
Good Lay Summary Practice is the guideline for implementation, not the obligation itself. The obligation to provide a results summary in the relevant case arises from Regulation (EU) No 536/2014, while GLSP offers concrete recommendations for working methods and comprehensibility. Compliance with GLSP therefore does not replace an assessment of whether the legal requirements and the information required in the system are met.
The existing term ‘laienverständliche Ergebniszusammenfassung’ (lay-understandable results summary) refers to the outcome document. GLSP refers to the process and quality framework according to which this document can be developed. The summary differs from the scientific Clinical Study Report in terms of audience, language, and purpose; it is not an abridged regulatory submission.
The summary should answer the audience’s questions about why the study was conducted, who participated, what was investigated, and what results emerged. Numbers may be used if their meaning is explained; isolated percentages or technical abbreviations do not serve the purpose. Even a negative or inconclusive result belongs in an understandable presentation. The Guidance thus aims for an objective presentation of results rather than communication that only highlights favorable findings.
Comprehensibility is not solely a matter of short sentences. Readers must also be able to recognize whether the study was completed, how many people participated, and whether the intervention was investigated against a comparator treatment. GLSP supports a presentation that explains such facts without individualizing participants. This keeps the text informative while respecting the confidentiality of the individuals who participated in the trial.
Relevance for clinical trials
A well-planned lay summary requires robust, clearly explainable results from the final analyses. Safety events, treatment groups, study duration, and the meaning of endpoints must be adequately presented for readers without statistical or medical training. If authors are only involved shortly before publication, translation, expert review, and feedback from laypersons are often difficult to integrate into the study’s final planning.
Full-service CROs like Mediconomics support GLSP through a project plan for summary development, coordination with data management and medical writing, and organization of comprehensibility checks. Translation management can verify the content equivalence of local language versions, while Regulatory Affairs supports the classification of results documents related to CTIS. This ensures that the lay version is developed from approved study data and not from preliminary presentation slides.
Frequently Asked Questions (FAQ)
Is a Lay Summary the same as a scientific abstract?
No. An abstract is aimed at expert readers and usually follows the language of the scientific publication. The lay-understandable results summary explains the same or related facts for non-experts.
Why does GLSP treat translations as a separate work step?
Comprehensibility and meaning can be lost when changing languages. The Guidance therefore considers translation as part of quality-assured preparation.
Can the Lay Summary be copied directly from a Clinical Study Report?
No. The Clinical Study Report has a different target audience and level of detail. Its data can be a source, but must be prepared in a lay-friendly manner.
Regulatory References
- Regulation (EU) No 536/2014, Article 37 — Regulates the submission of clinical trial results.
- Regulation (EU) No 536/2014, Annex V — Lists content for lay summaries of results.
- Good Lay Summary Practice Guidance of the European Commission — Recommends planning, preparation, translation, and dissemination.
- EudraLex Volume 10 — Compiles guidelines and supplementary documents for clinical trials in the EU.