Does readability or user testing of a patient leaflet catch wrong words?
Not reliably. In the EU, a package leaflet has to reflect consultations with target patient groups, and user testing is one accepted way to do that. A test checks whether people can find key information, understand it and act on it. It isn't a word-by-word read, and the European Commission's guideline says testing itself doesn't improve the quality of the information.
This page is general information, not legal or regulatory advice.
What the rules say
- EU law: Article 59(3) of Directive 2001/83/EC says the leaflet must reflect consultations with target patient groups so that it is legible, clear and easy to use. The results go to the competent authority with the application.
- The guideline: the European Commission's readability guideline (Revision 1, January 2009) calls user testing a development tool that shows where there are problem areas to fix. It also covers type size, layout, headings and plain wording.
- Translations: the guideline says consultation in one EEA language is normally enough, and that translation quality should get a thorough review by the applicant once the tested leaflet is final.
Why a user test can miss a wrong word
Our view: a test asks people about a set of key points, such as side effects, warnings and how to take the medicine. A wrong word in a line the questions don't touch can pass. Testing is usually done in one language, so a wrong word that enters during translation comes after the test. The guideline itself puts that check on the applicant's translation review.
What to add
Practice advice: after testing and after each translation, read every high-stakes line for meaning in every language. Watch words a tester wouldn't be asked about, such as route words. Made-up example: a line meant to say "oral" that says "aural" sends the reader to the ear, and a participant asked a different question would never notice.
See EU QRD template wording, bilingual and translated labels and Medication Guide and IFU errors.
Sources
- EUR-Lex: Directive 2001/83/EC (consolidated text)
- European Commission: Guideline on the readability of the labelling and package leaflet (Revision 1, 2009)
Last reviewed: October 14, 2026
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FAQ
What is readability or user testing of a leaflet?
A test with people from the target population to check they can find, understand and act on key information in a package leaflet. In the EU it is one accepted way to meet the consultation requirement in Article 59(3) of Directive 2001/83/EC.
Does user testing require exact wording?
No. It tests whether people can find and understand key information, not each word. Required wording comes from other rules and templates. This is general information, not legal advice.
Can a leaflet pass user testing and still have a wrong word?
Yes, in our view. A test covers a set of key questions, usually in one language, so a wrong word elsewhere or added in translation can pass.