11 Feb Multilingual informed consent forms that do not hold up your trial: a practical guide for CROs in 2026

In many projects, multilingual informed consent is the document that ultimately determines whether your timeline stays on track or falls apart. Few things are more frustrating for a CRO than having everything ready for site activation, only to become stuck because the consent forms in certain countries fail to convince the ethics committees.

By 2026, with trials becoming increasingly global, multilingual informed consent has become a genuine operational bottleneck. The good news is that with a clear language strategy, you can transform that bottleneck into a predictable and defensible workflow for regulators.

Why informed consent is now a critical issue

With the European Clinical Trials Regulation, Member States have tightened their requirements for information that is clear, easy to understand, and available in the patient’s own language. Reference documents emphasise that information for participants must be presented in plain language and in the local language of each country.

At the same time, health literacy data in Europe show that a significant proportion of the adult population has difficulty understanding complex health information. When multilingual informed consent is not adapted to this reality, ethics committees are more likely to raise questions, request clarifications and issue observations.

Simply translating “correctly” is no longer enough. Now committees scrutinise whether the text is truly understandable. And that directly impacts approval times.

What regulators and ethics committees expect

Beyond the specificities of each country, three points appear consistently across guidance:

• Local language: English alone is not sufficient; information must be provided in the participants’ language and culturally adapted.
• Clear language: unnecessary technical terms, long sentences, and confusing structures should be avoided. Short sentences, active voice, and step-by-step explanations are recommended.
• Consistency between documents: what is promised in the consent must match the protocol, investigator’s manual, and recruitment materials.

For a CRO, this translates into something very concrete: multilingual informed consent cannot be treated as a “last week” task before submission.

Linguistic errors that delay trials

From the perspective of an experienced medical translation team, these are the errors that cause the most delays:

• Literal translations that follow English syntax and produce unnatural-sounding texts that are difficult for patients to understand.
• Inconsistencies in key terms (e.g., “serious adverse event”, “optional procedures”, “biological samples” being called by various names in the same document or between annexes).
• Discrepancies between versions: the main consent form, annexes and protocol are out of sync, with amendments reflected in some documents but not in the patient-facing text.
• Information overload: endless paragraphs that mix objectives, procedures, risks, alternatives and privacy aspects without separating blocks.
• Lack of cultural adaptation: examples, references or metaphors that do not make sense in certain countries or population segments.
• Each of these issues can lead to ethics committee comments, requests for rewriting and, in extreme cases, the need to re-obtain consent.

Recommended workflow for CROs

To prevent multilingual informed consent from becoming a barrier, the CRO should:

• Involve linguists from the design stage
• Share protocol, global templates, and regulatory expectations.
• Align key terminology and tone of communication from the outset with the person who will manage the multilingual informed consent.
• Define glossaries and style guides per study
• List clinical and regulatory terms with their approved translation.
• Set criteria for easy reading: maximum sentence length, use of examples, order of information.
• Work with validated local templates
• Use country-specific templates that have already been accepted by ethics committees.
• Maintain consistent structures: what comes first, what is repeated, and what is placed in appendices.
• Ensure two-step expert review
• A medical translator and a reviewer with clinical or regulatory experience.
• Final review by local team to adjust cultural nuances and specific references.
• Plan the maintenance
• Define a clear procedure for updates following protocol amendments.
• Establish version control to ensure all languages are aligned.

Quick checklist for your next multinational trial

Before submitting to committee, confirm that:

• All consent forms are available in the participants’ own language.
• You have used unified glossaries for critical terms.
• The reading level is adjusted to a person with low health literacy.
• Information about risks and benefits is distributed in clear blocks.
• All annexes and supporting materials say the same thing in all languages.
• There is a plan to update the versions after protocol amendments.
• You can explain the process followed for each multilingual informed consent form.