'Femi Fajimi

Writing Lay Summaries: What I Didn’t Expect to Learn as a Regulatory Writer

By Femi Fajimi | 27 November 2025 

(Educational content. No confidential information included.)

Introduction 

When I started learning regulatory medical writing, I assumed that lay summaries were “scientific findings rewritten in simpler language.” I expected the usual tasks: reducing jargon, shortening sentences, and clarifying statistics. 

But in a recent lay summary, I contributed to, I realised the role extends far beyond simplification. Writing for the public is a responsibility that carries ethical weight. The reader may be a patient, a caregiver, or someone making a life decision based on your explanation. 

A lay summary is not merely a communication requirement under EU CTR 536/2014; it is a document that directly shapes how the public understands clinical research, risk, and medical evidence. And that comes with demands I hadn’t initially appreciated. 

What Surprised Me Most 

1. Every word can influence trust 

In regulatory writing, we aim for precision, but in a lay summary, precision must coexist with emotional sensitivity. For example, describing a serious adverse event in technical terms is easy. Explaining it in a way that is truthful, neutral, and not frightening requires balance. I learned that the public interprets tone as much as content. A sentence such as: 

“Five participants experienced serious complications, though none were related to the study drug,” has a very different emotional effect from: 

“A few participants became seriously unwell during the study, but the investigators reviewed the events and confirmed that the study medicine was not the cause.” Both are accurate. But the second acknowledges the human experience behind the data. 

2. “Plain language” is not the same as “simplistic” 

Avoiding jargon is expected. But what I didn’t expect was how difficult it is to simplify without losing scientific meaning. 

Take a phrase such as “non-inferiority margin.” 

You cannot simply remove it: the concept affects the interpretation of the entire trial. Yet it must be explained in a way that is accessible: 

“The study was designed to show that the new medicine works at least as well as the existing treatment.” 

Regulators, especially the MHRA and EMA, now expect lay summaries that retain scientific integrity, not ones that dilute it. 

3. Transparency is not optional 

The lay summary must present the entire picture: what worked, what did not work, and what uncertainties remain. 

These include: 

• Limitations 

• Missing data 

• Unexpected observations 

• Safety signals, even if minor 

It is tempting to focus on positive results. But transparency is the foundation of public trust. 

4. It must reflect regulatory accuracy, not the writer’s interpretation 

One lesson that stayed with me: The lay summary is not a “creative rewrite” of the clinical study report. 

It must follow: 

• the protocol 

• the SAP 

• the CSR 

• and the final approved results 

Every number must match. 

Every statement must be traceable. 

Every conclusion must reflect what the sponsor and statisticians confirmed. 

This is where regulatory writing discipline becomes essential. 

5. It forces you to think like a patient, not a scientist 

Perhaps the biggest shift for me was recognising that the reader is not trying to assess p-values or confidence intervals. They are asking: 

What does this mean for me? 

Is it safe? 

Does it work? 

What should I expect? 

This required a different mindset, one that blends empathy with scientific accuracy. 

Practical Lessons I Will Take Forward 

✔ Structure is everything 

✔ Visuals help more than expected 

✔ Collaboration strengthens clarity. 

✔ Read aloud to check readability 

✔ Always use established frameworks 

Including: 

• EU CTR 536/2014 Annex V 

• HRA/MHRA plain language guidance 

• EMA’s Layperson Summary Guidance (2022 update) 

• ISO plain-language principles 

Why Lay Summaries Matter More Than We Think 

As regulatory writers, we engage deeply with complex data, statistical methods, and regulatory frameworks. But lay summaries remind us of something fundamental: 

Science ultimately exists for people. 

Not agencies. Not companies. Not writers. 

People who need information they can trust. 

Crafting a lay summary that is clear, sensitive, and accurate is one of the most meaningful contributions a writer can make to public health. 

Conclusion 

Working on a lay summary taught me far more than I expected, not just about simplifying science, but about communication ethics, public trust, and the responsibility this role carries. 

I now see lay summaries as one of the exceptional training grounds. They challenge your clarity, discipline, empathy, and ability to translate evidence responsibly.