---
title: Patient Information Under MDR: Writing for Lay Users
description: MDR Annex I Section 23 and Article 32 force patient information into plain language. Here is how to write lay-user content auditors and patients accept.
authors: Tibor Zechmeister, Felix Lenhard
category: Technical Documentation & Labeling
primary_keyword: patient information lay users MDR
canonical_url: https://zechmeister-solutions.com/en/blog/patient-information-lay-users-mdr
source: zechmeister-solutions.com
license: All rights reserved. Content may be cited with attribution and a link to the canonical URL.
---

# Patient Information Under MDR: Writing for Lay Users

*By Tibor Zechmeister (EU MDR Expert, Notified Body Lead Auditor) and Felix Lenhard.*

> **Patient information under MDR is the body of text a lay user. A patient, a carer, or any non-professional. Has to be able to understand before and during use of the device. The obligation comes from Annex I Chapter III Section 23.1 of Regulation (EU) 2017/745, which requires information supplied with the device to be in a form easily understood by the intended user. For implantable and Class III devices, Article 32 adds a Summary of Safety and Clinical Performance with a mandatory lay-user section written at a reading level non-specialists can follow. Writing for lay users is not a stylistic preference. It is a regulatory requirement with its own validation path under EN 62366-1:2015+A1:2020.**

**By Tibor Zechmeister and Felix Lenhard. Last updated 10 April 2026.**

---

## TL;DR

- Annex I Chapter III Section 23.1 of Regulation (EU) 2017/745 requires information supplied with the device to be in a form easily understood by the intended user, taking their training and knowledge into account. For a lay user, that means plain language at a reading level a non-specialist can follow.
- For implantable and Class III devices (with narrow exceptions), Article 32 of Regulation (EU) 2017/745 requires a Summary of Safety and Clinical Performance (SSCP) that contains a section written specifically for the intended patient, in clearly understandable language.
- Lay-user content is a usability engineering deliverable, not a marketing deliverable. EN 62366-1:2015+A1:2020 governs the validation. The summative evaluation has to involve representative lay users, not clinicians.
- Translation compounds every editorial decision. Every simplification made in the English master propagates into every Member State language under Article 10(11). Long, dense patient text is expensive in every direction.
- The test for lay-user content is behavioural, not aesthetic. Can a representative patient, in the use environment, follow the instructions and identify the warnings without external help? If not, the content is non-compliant regardless of how polished it reads.

---

## Why patient information is the hardest writing in the file

Professional users forgive a lot. A clinician reading a device IFU can fill in missing context from training. A patient cannot. A patient reading a leaflet at home, worried, possibly on medication, possibly with impaired vision, has none of the scaffolding the clinical reader brings. If the text assumes knowledge the patient does not have, the information fails. And the failure shows up as an incident, not as a reviewer comment.

Founders underestimate this because most of the team reads and writes like clinicians or engineers. The draft leaflet goes through internal review and everyone understands it, which is the trap. Everyone on the internal review team shares vocabulary the actual patient does not. The draft reads fine to the team and is unreadable to the intended user. The first time anyone notices is when the Notified Body runs its usability check, or worse, when a serious incident report lands on the desk and traces back to a misread instruction.

Patient information is the hardest writing in the technical file because the people writing it are almost never the people who have to use it.

## Where MDR requires lay-user content

There are three distinct places in Regulation (EU) 2017/745 where lay-user content is required, and they are not the same.

**Annex I Chapter III Section 23.1. The general obligation.** Section 23.1 sets the principle that all information supplied with the device must be in a form easily understood by the intended user, taking their training and knowledge into account. (Regulation (EU) 2017/745, Annex I, Chapter III, Section 23.1.) For any device whose intended user group includes patients, carers, or lay users, this obligation puts plain-language discipline on the label, the packaging information, and the IFU.

**Annex I Chapter III Section 23.4. The IFU content.** Section 23.4 is the mandatory list of what the IFU must contain. Every item on that list applies to lay-user IFUs just as it applies to professional-user IFUs. The difference is that the language has to be adjusted to the intended user group. (Regulation (EU) 2017/745, Annex I, Chapter III, Section 23.4.) A lay-user IFU does not get to skip required items; it has to express them in vocabulary the lay user can follow.

**Article 32. The SSCP lay summary.** For implantable devices and Class III devices (with narrow exceptions defined in the article), Article 32 requires a Summary of Safety and Clinical Performance. Article 32(2) requires the SSCP to be written in a way that is clear to the intended user and, where relevant, to the patient, and explicitly requires a section written for the intended patient. (Regulation (EU) 2017/745, Article 32.) The patient-facing section of the SSCP is the most explicit lay-content requirement in the regulation.

These three sources interact. Section 23.1 sets the general principle. Section 23.4 lists what has to be in the IFU. Article 32 adds a standalone lay document for higher-risk devices. A single patient-facing device can be subject to all three at once.

## What "easily understood" actually means

Section 23.1 is regulation, not style guide. It does not specify a reading level, a sentence length, or a vocabulary list. What it specifies is a result: the intended user has to be able to understand the information, taking their training and knowledge into account. The level of plain language is set by the use specification. Who the intended user is, what they know, what they do not know, what their environment is. For a lay user, that anchor point is a non-specialist with ordinary literacy, possibly under stress, possibly with sensory or cognitive limitations that are predictable for the patient population.

Working definitions the regulation implies, rather than states:

- Sentences short enough that a non-specialist can parse them on one reading.
- Vocabulary the intended user already uses. Technical terms spelled out on first use and paired with plain-word equivalents.
- One instruction per step. No compound instructions that combine "do X while checking Y unless Z."
- Warnings phrased so the hazard and the action are both explicit.
- No abbreviations that are not spelled out.
- No internal codenames, no marketing adjectives, no sentences built for legal defence instead of patient comprehension.

"Plain" is not "dumb." A precise plain sentence is harder to write than a dense clinical one. The discipline is precision with words the user already knows.

## MDR phrasing constraints patient writers trip over

Several phrasing habits come from clinical or regulatory writing and fail when ported into lay content.

- **Passive constructions.** "The device is to be inserted" hides the agent. A lay user needs "Insert the device" or "Your nurse will insert the device," depending on who acts.
- **Noun stacks.** "Post-procedure wound site assessment" becomes "Check the wound after the procedure."
- **Double negatives.** "Not contraindicated unless the patient does not tolerate…" is unusable in a leaflet.
- **Legal-defensive phrasing.** "Users should consult a healthcare professional in the event of any adverse reaction" is vague. "If you feel pain, fever, or swelling, contact your doctor immediately" is actionable.
- **Risk-file vocabulary ported verbatim.** ISO 14971 uses terms like "residual risk" and "foreseeable misuse." A lay user needs the translation, not the source phrase.
- **Clinical register for symptoms.** "Dyspnoea" is "shortness of breath." "Erythema" is "redness of the skin." Every such swap has to be deliberate and traceable.

None of these are optional polish. Each one is a use-error risk under EN 62366-1:2015+A1:2020. A warning the user does not parse is a warning that is not implemented.

## Translation impact. Plain language is cheaper in every language

Article 10(11) of Regulation (EU) 2017/745 requires the information supplied with the device to be in the official Union language or languages determined by the Member State in which the device is made available. (Regulation (EU) 2017/745, Article 10(11).) For lay-user devices, most Member States require the national language. Every lay-user document is therefore a multi-language document, and every editorial decision in the English master multiplies.

Two implications every founder needs to internalise before writing starts.

First, shorter is cheaper. Every additional sentence in the master translates into every language. A 20-percent cut in the master is a 20-percent cut in every future translation bill and every future revision cycle.

Second, simpler is more accurate. Dense source text produces drift in translation. Translators paraphrase what they cannot parse, and paraphrase diverges from the master. Plain source text produces clean translations because every sentence means one thing. Translation drift is a document control finding waiting to happen.

The discipline that produces compliant lay-user content is the same discipline that produces cheaper multi-language compliance. It is not a trade-off.

## Test: good vs bad lay text

A worked comparison. Suppose the device is a home-use injector and the risk file has identified a residual risk around reusing the same injection site.

**Bad. Clinical register, passive voice, vague action.**

> "Rotation of injection sites is recommended to avoid lipohypertrophy and local tissue reactions. Users experiencing persistent induration or erythema at a prior administration site should refrain from repeat administration at the same site and consult a healthcare professional."

**Good. Plain, active, actionable.**

> "Change the place where you inject each time. Do not use the same spot twice in a row. If a previous spot is still hard, lumpy, or red, pick a different spot and tell your doctor."

Both sentences contain the same clinical content. The second is shorter, safer, translates cleanly, and survives summative evaluation because a representative lay user will do what it says. The first will produce use errors the audit will eventually find.

The same comparison holds for every sentence in a lay-user document. It is not one edit pass. It is a rewrite discipline applied line by line, anchored in the use specification.

## The writing playbook. Ship

A reproducible sequence for producing lay-user content that survives audit and summative evaluation.

1. **Anchor in the use specification.** Write down explicitly who the intended lay user is. Age range, literacy assumptions, language, environment, state of mind when reading. Every later decision references this.
2. **Start from Section 23.4, not from a blank page.** List every mandatory IFU item. Write each one first in plain language, then check that the regulated information is fully present.
3. **Pull warnings from the ISO 14971 risk file.** Every residual risk controlled by information for safety produces a warning. Translate the risk-file vocabulary into plain language. Keep the traceability. The risk file references the IFU section, not the other way around.
4. **Pull contraindications from the clinical evaluation.** Specific patient groups, conditions, circumstances. Plain words, concrete examples where possible.
5. **For implantable and Class III devices, draft the Article 32 lay section in parallel with the IFU.** Keep the SSCP lay section consistent with the IFU lay content. Contradictions between the two are audit findings.
6. **Read aloud.** Anything that trips the reader's tongue will trip the lay user's comprehension. Rewrite every stumble.
7. **Run summative evaluation under EN 62366-1:2015+A1:2020 with real lay users.** Representative members of the intended patient group, in the intended environment, performing the intended tasks with the document in front of them. Record every use error. Revise the document, not just the device.
8. **Lock the master before translation.** Every change after lock costs every language. Do not translate a draft.
9. **Put every translation under document control per EN ISO 13485.** Version the translations with the master. Re-validate after every substantive revision.
10. **Subtract at the end.** Read the final document line by line and cut every sentence that does not trace to Section 23.4, a risk control, a clinical conclusion, or an Article 32 obligation. The cut almost always removes 15 to 30 percent without losing a required element.

This playbook applies equally to the IFU for a lay-user device, the patient leaflet, and the Article 32 SSCP lay section. The sources differ; the discipline does not.

## Reality Check. Where do you stand?

1. Does your use specification explicitly define the lay user. Literacy, language, environment, state of mind. Or is "patient" the whole description?
2. For every residual risk in your ISO 14971 risk file controlled by information for safety, is there a plain-language warning in the lay-user document that a representative patient would actually follow?
3. Can a non-specialist, reading at ordinary literacy level, parse every sentence of your lay-user content on a single reading?
4. Have you run summative evaluation under EN 62366-1:2015+A1:2020 with representative lay users. Not clinicians, not your own team. On the shipped document?
5. If your device is implantable or Class III, does your Article 32 SSCP contain a lay-user section written in clearly understandable language, and does it agree with the IFU lay content line by line?
6. Is every translation of the lay-user document under document control, and does every language version match the master after every revision?
7. Does every sentence in the document trace to a Section 23.4 item, a risk control, a clinical conclusion, or an Article 32 obligation?

## Frequently Asked Questions

**Which devices require patient information written for lay users under MDR?**
Any device whose intended user group includes patients or lay users triggers the plain-language obligation in Annex I Chapter III Section 23.1. On top of that, implantable devices and Class III devices (with narrow exceptions in Article 32) require a Summary of Safety and Clinical Performance with a dedicated lay-user section under Article 32 of Regulation (EU) 2017/745.

**What reading level does the MDR require for lay-user text?**
Regulation (EU) 2017/745 does not specify a numerical reading level. Section 23.1 requires the information to be in a form easily understood by the intended user, taking training and knowledge into account. For a typical lay-user population, that implies plain language at a non-specialist level. The test is behavioural. Can a representative user follow the text in the intended environment. Not numerical.

**What is the Article 32 SSCP lay summary and who writes it?**
The Summary of Safety and Clinical Performance is a document required for implantable and Class III devices under Article 32 of Regulation (EU) 2017/745. It contains a section written for the intended patient, in clearly understandable language. The manufacturer drafts it; the Notified Body validates it as part of conformity assessment. It is uploaded to Eudamed and is publicly accessible.

**Can we just simplify the clinical IFU and call it the patient version?**
No. The patient version has to be built from the use specification of the lay user, not by editing down a clinical document. Simplified clinical text typically leaves clinical register phrases in place, omits contextual information a clinician had and a patient does not, and fails summative evaluation with real lay users. The patient document is a separate deliverable built from the same source facts.

**Does the patient information need its own usability validation?**
Yes. EN 62366-1:2015+A1:2020 requires summative evaluation of the user interface, and the information supplied with the device is part of the user interface when the device is intended to be used with it. For a lay-user device, the validation has to involve representative lay users in the intended environment, not internal reviewers.

**How do translation obligations interact with the lay-user writing?**
Article 10(11) of Regulation (EU) 2017/745 requires information in the official Union language or languages set by each Member State. For lay users, most Member States require the national language. Every editorial decision in the master propagates into every translation. Shorter, plainer master text produces cheaper, cleaner, and less drift-prone translations.

## Related reading

- [The Instructions for Use (IFU) Under MDR: How to Write Compliant IFUs](/blog/instructions-for-use-mdr-compliant) – the Section 23.4 requirements the lay-user IFU has to satisfy item by item.
- [The Summary of Safety and Clinical Performance (SSCP) Under MDR Article 32](/blog/sscp-mdr-article-32) – the lay-section obligation for implantable and Class III devices.
- [Multi-Language Labeling Under MDR for Startups](/blog/multi-language-labeling-mdr-startups) – the Article 10(11) translation obligations and how to run them without burning the budget.
- [Usability Engineering Under MDR and EN 62366-1](/blog/mdr-usability-engineering-en-62366-1) – summative evaluation is where lay-user content is validated for real.
- [Labels Under MDR: Section 23.2 Requirements in Practice](/blog/mdr-label-requirements-section-23-2) – the label side of information supplied with the device.

## Sources

1. Regulation (EU) 2017/745 of the European Parliament and of the Council of 5 April 2017 on medical devices, Article 10(11) (language of information supplied with the device), Article 32 (Summary of Safety and Clinical Performance), Annex I, Chapter III, Section 23.1 (general principles for information supplied with the device), Section 23.4 (information in the instructions for use). Official Journal L 117, 5.5.2017.
2. EN 62366-1:2015+A1:2020. Medical devices. Part 1: Application of usability engineering to medical devices (IEC 62366-1:2015 + IEC 62366-1:2015/A1:2020).

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*This post is part of the Technical Documentation & Labeling cluster in the Subtract to Ship: MDR blog. Authored by Felix Lenhard and Tibor Zechmeister. Patient information is where regulatory writing either earns its keep or becomes the reason for a serious incident. A short, plain, disciplined lay-user document is not a stylistic choice. It is the regulated form the MDR actually requires.*

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*This post is part of the [Technical Documentation & Labeling](https://zechmeister-solutions.com/en/blog/category/technical-documentation) cluster in the [Subtract to Ship: MDR Blog](https://zechmeister-solutions.com/en/blog). For EU MDR certification consulting, see [zechmeister-solutions.com](https://zechmeister-solutions.com).*