Making clinical trial participation truly informed — one consent form at a time.


Informed Consent in Clinical Trials: More Than Just a Signature

Informed consent is the ethical foundation of all clinical research involving human participants. It ensures that participants understand the purpose, risks, benefits, and procedures of the study and that they voluntarily agree to take part. But what happens when the language used in consent forms is far above the participant’s reading level? That gap undermines the very concept of “informed” consent.

When participants misinterpret study procedures, overlook risks, or skim through complex consent forms, they risk misunderstanding their rights or responsibilities. This can lead to dropout, inaccurate data, or ethical concerns—all of which compromise research quality and trust.

The Problem: Consent Forms Are Often Too Complex

The average American adult reads at a 7th to 8th grade level,1 yet many consent documents—especially those developed in academic or medical settings—are written at a college level or higher. Federal guidelines recommend materials be accessible at or below an 8th grade level.

When consent forms are filled with technical jargon or legal language, they can intimidate or exclude people with limited literacy, English as a second language, or cognitive challenges. For vulnerable and historically marginalized populations, overly complex forms deepen existing distrust in the medical system.

Terms like “randomized,” “intervention arm,” “prospective cohort,” or “HIPAA authorization” are routine in the research world, but for many participants, they are barriers to understanding.

The Risks of Poor Comprehension in Research

A recent review of COVID-19 vaccine trial consent forms found they exceeded a 9th grade reading level and took an average of 35 minutes to read.2 In reality, very few people spend that much time reading consent materials, especially when they’re ill, stressed, or unfamiliar with medical terminology.

Participants facing chronic illness, recent diagnoses, or complicated treatment regimens may not have the bandwidth to process lengthy, technical documents. Without clarity, these forms become a barrier to participation and ethical engagement.

Addressing Health Literacy in Informed Consent

Improving consent readability isn’t about oversimplifying. It’s about making vital information accessible, respectful, and useful. At M&B Sciences, we believe in clear communication as a form of respect. We’ve adopted the following best practices:

  1. Reduce Length Where Possible
    We aim to keep consent forms under four pages (1,000–1,250 words). Long forms can lead to skimming, which defeats the purpose of informed consent.
  2. Use Plain Language
    Avoid medical or legal jargon. Say “blood draw” instead of “venipuncture,” and use active voice (“We will call you”) rather than passive constructions (“You will be contacted”).
  3. Be Clear and Specific
    Describe side effects, study procedures, and data use clearly. Avoid vague terms or ambiguous phrasing.
  4. Structure for Readability
    Use short paragraphs, bullet points, and headers. Organize content around key questions:
    • What is this study about?
    • Why am I being asked to join?
    • What will I be asked to do?
    • What are the risks or discomforts?
    • What happens if I say no?
  5. Define Technical Terms with Examples
    Don’t assume knowledge of terms like “placebo,” “randomized,” or “confidentiality.” Use relatable examples.
  6. Test Readability
    Use tools like the Flesch-Kincaid Grade Level and aim for a 6th to 8th grade reading level unless justified otherwise.
  7. Provide Verbal and Visual Support
    Offer videos, diagrams, or verbal consent options for those with visual impairments, limited literacy, or cognitive differences. Visual aids help explain timelines or procedures more effectively than text alone.
  8. Pilot Test with Real Participants
    Share draft consent forms with patient advisors or community representatives. Ask them to explain the study back to you in their own words.

Ethical Research Starts with Understanding

Informed consent isn’t just a regulatory requirement—it’s the starting point of a respectful and ethical relationship with every participant. Researchers must meet people where they are, using clear, empathetic language that empowers individuals to make informed decisions.

At M&B Sciences, we believe that without true understanding, there is no true consent. When we prioritize clarity and inclusion, we build trust, strengthen research integrity, and improve outcomes for everyone involved.

Want to make your research more inclusive and patient-centered? Contact M&B Sciences to learn how we can support clear, ethical, and effective consent processes in your next study.

References

  1. U.S. Adults Score on Par With International Average in Literacy Skills, Below International Average in Numeracy and Problem-Solving Skills in Survey of Adult Skills. December 10, 2024. https://nces.ed.gov/whatsnew/press_releases/12_10_2024.asp
  2. Emanuel, E. J., & Boyle, C. W. (2021). Assessment of length and readability of informed consent documents for COVID-19 vaccine trials. JAMA Network Open, 4(4), e2110843-e2110843. https://pmc.ncbi.nlm.nih.gov/articles/PMC8082317/