Plain Language

Plain Language is a clear way of writing and sharing information so that people can understand it the first time they read or hear it.

plain languageAccording to, plain language helps the reader:

  • Find what they need
  • Understand what they find
  • Use what they find to meet their needs

Given that clinical research communications can be very technical and complex, using plain language can help clearly explain information so that the target audience has a better chance of understanding.

In this section are tips, as well as examples, of how to apply plain language techniques within the clinical research context.

Plain Language in Clinical Research

Readability Testing

Plain Language Resources

Plain Language in Clinical Research

Plain language helps participants make an informed decision and follow the study instructions.

Remember: Even those with higher health literacy skills want health information that is understandable, meaningful to them, and easy to use

Try some of these plain language tips:

  • Present what the intended audience should know or do in a way that makes it easy to take action.
    • For example, to find out if you are able to join the study we will do some screening tests that include answering some questions and taking some blood
  • Determine key concepts and messages based on the knowledge of the intended audience and prioritize those in the document.
  • For example “use” instead of “utilize”
  • For example “high blood pressure” instead of “hypertension
  • Plain language does not mean removing key technical terms.
    • Instead, medical, research, or legal concepts and phrases that must be included in a communication should be explained within the document or in a separate document that defines the complex terms in clear, understandable ways.
    • This can be further supported by:
  • Using visuals and word/picture pairings to help explain the concept.
  • Providing an explanation using a few short, simple sentences.
  • Using analogies as examples to show how a concept works
  • Active Voice is easier to understand than the Passive Voice and usually makes sentences shorter.
  • An active tone leaves less room for error and participants receive clear instructions regarding their participation and compliance.


The study medicine will be taken by all participants All participants will take the study medicine
Arrival to the office 15 minutes prior to your study visit is recommendedPlease arrive at the office 15 minutes before your study visit
Interviews will be conducted by researchers at the study facilityResearchers will conduct interviews at the study facility
Heart rate and blood pressure will be measured by trained nursing professionalsNurses will take your heart rate and blood pressure.
The effect of tamoxifen on breast cancer was studied by researchersResearchers studied the effect of a drug called tamoxifen on breast cancer.

Readability Testing

Readability tests can help frame your revision process and tell you where you might need to make changes. But they are generally not considered to be sufficient on their own and do not necessarily equate to better understanding of the material.

Testing your materials with people like your study population, and including people with low literacy, is the best way to know whether your document is understandable.

Note: People usually read about five grade levels below the level of education they have finished

Tailor these to include criteria for assessment that are most relevant to determining whether the content is right for the intended audience.

For example, you can use these checklists to confirm that the eligibility criteria on recruitment flyers are described using simple explanations or check that the purpose of the research study is clearly stated in the consent form.

Good place to start if you are working with existing contentOver-simplification of a complex issue – readability is more than an algorithm
Good place to start to gauge the reading level of new content being developedLimits defining difficult or complex words because it would involve extra words or sentences
Standardizes readability levels across multiple documents if the same test is usedLack of consistency between different readability tests (and even the same reading test offered on different websites)
Easy to use Many different tests to choose from
Free to use from many sourcesDiscourages using well known words that are longer (i.e. Television)

Writing and editing software that also calculates reading grade level:

Attention: The internal data of table “4” is corrupted!

Plain Language Resources

Use Assessments.  A best practice is to go beyond readability formulas. Use assessment checklists to review specific criteria as part of the readability assessments.

Here are a few favorites: