'Femi Fajimi

Lay Summaries in Clinical Trials: A Beginner’s Perspective on Making Research Understandable 

By ‘Femi Fajimi | 29/ April/2025 

As a beginner regulatory medical writer, I am learning that writing clinical trial documents involves more than technical precision. Increasingly, regulatory requirements demand that clinical research results be communicated to the public in a clear, factual, and understandable way. 

One important document supporting this goal is the Lay Summary, also known as the Plain Language Summary (PLS) of clinical trial results. Preparing a lay summary requires translating complex scientific data into language that can be understood by individuals without a medical background without compromising accuracy or regulatory standards. 

In this post, I share what I am learning about Lay Summaries, their role in clinical research transparency, and what beginner writers like me should focus on when preparing them. 

What is a Lay Summary? 

According to the EU Clinical Trials Regulation (EU CTR 536/2014) and the EMA guidance on the Summaries of Clinical Trial Results, a Lay Summary is: 

A summary of the clinical trial results, written in language understandable to the general public, including trial participants. 

Lay Summaries must provide objective, non-promotional, and transparent information about: 

Why the study was done 

How it was conducted 

What the study found 

What the results mean for patients and healthcare 

They must ensure trial participants, and the public can access research findings, fulfilling ethical commitments to transparency and public trust. 

What Should a Lay Summary Include? 

A Lay Summary typically follows a standard structure based on the EU Recommendations 2017 and TranspariMED standards, including: 

Study Title and Purpose 

A clear and straightforward explanation of the study’s goals. 

Who Took Part 

Description of participant demographics (e.g., number, age ranges, gender distribution). 

Why the Study Was Needed 

Background on the disease/condition and unmet needs. 

What Treatment Was Tested 

Simple description of the investigational product or therapy. 

What Happened During the Study 

Summary of the trial design, treatments given, and key study procedures. 

What Were the Results? 

Summary of the main findings, including efficacy and safety outcomes. 

What Were the Side Effects? 

Simple, honest reporting of any observed side effects or adverse events. 

What Do the Results Mean? 

Brief explanation of the implications for patients and future research. 

Who Sponsored the Study? 

Disclosure of the company or institution funding the study. 

Further Information 

How do you find more detailed results or contact details for queries? 

Key Principles I Am Learning for Writing Lay Summaries 

As a beginner, I understand that writing a Lay Summary requires balancing scientific integrity and simplicity. 

Some essential principles include: 

Use Plain Language 

Replace technical terms with simple words without oversimplifying clinical meaning. For example: 

✅ “High blood pressure” instead of “hypertension” 

Be Factual, Not Promotional 

State results objectively. Avoid words like “excellent,” “exciting,” or “promising” unless supported by strict statistical findings. 

Explain Risks Honestly 

Side effects should be described openly, with clear incidence rates if known. 

Respect Participant Perspectives 

The summary should be written with the dignity of participants in mind, acknowledging their contribution to medical research. 

Keep Sentences Short and Clear 

Aim for sentences under 20 words where possible. 

Avoid Assumptions 

The reader should not be expected to have scientific training. 

Regulatory Expectations for Lay Summaries 

In the EU, Lay Summaries are mandatory under EU CTR 536/2014, Article 37. 

In the UK, following Brexit, transparency commitments under HRA (Health Research Authority) also encourage the publication of lay Summaries. 

EMA, TranspariMED, and Cochrane organisations provide detailed guidelines on how to prepare high-quality summaries. 

In some cases, sponsors are advised to involve patient representatives or plain language reviewers to improve the accessibility of their summaries. 

➡️ View Sample

References: 

European Medicines Agency (EMA). Guideline on Summaries of Clinical Trial Results for Laypersons. 2017. 

EU Regulation No. 536/2014. Clinical Trials Regulation. 2014. 

Health Research Authority (HRA). Transparency and Results Reporting Guidance. 2022. 

Cochrane Handbook. Guidance on Plain Language Summaries. 2020. 

TranspariMED. Recommendations for Effective Clinical Trial Result Summaries. 2021. 

⚠️ Disclaimer 

This Lay Summary was developed for educational and demonstration purposes only. 

Dermalexiin (DLX-412), MolendiiP Pharma Ltd, and the described clinical trial (DERM-001) are fictional constructs. 

No real clinical study was conducted. 

This Lay Summary follows the key principles and structure recommended by the EU Clinical Trials Regulation (EU CTR 536/2014) and EMA guidance for Lay Summaries. 

However, certain technical details, regulatory formalities, and operational information have been summarised or omitted for simplicity. 

In a real-world submission, a Lay Summary would be adapted according to the specific study results, audience needs, and local regulatory requirements.