Writing Patient-Friendly Clinical Trial Materials: 3 Steps to Simplify Language & Increase Readability

by William McEwen
The clinical trials industry relies heavily on print and digital materials for patient recruitment and retention.


The clinical trials industry relies heavily on print and digital materials for patient recruitment and retention. To be effective, these materials must connect with the audience. There are many ways to make this connection, from writing clinical trial materials to design.

One way to disconnect is writing at a reading level that is too high. Overlooking the importance of readability can impede participation in trials.

It’s easy to make this mistake. Our audience likely has a reading level that is lower than our own. As life science professionals, we communicate in precise language. When we take our study from protocol to patient, a translation of sorts into a broader readability level is needed. Big words can be sublimely precise, but using them in patient materials puts you in danger of losing your reader. Reducing the reading level of our pieces when writing clinical trial materials for patients is important.

If writing at a broader reading level doesn’t come naturally to you, read on. (And a quick note – here we are addressing materials for adult audiences, not pediatric studies.)

Step 1

Write clinical trial materials at the reading level you most easily write to. You will look for ways to improve readability later.

Trying to accomplish too much can be stifling. Begin by getting the necessary information down on paper, and don’t worry about the reading level. Write each sentence the way you would normally, in a way that comes naturally to you.

As you move from rough draft to first draft — changing, fixing, and improving — perform all your necessary wordsmithing as usual. Again, don’t concern yourself with the readability level. That will come later.

And now that your first draft is done, it is time for the next step.

Step 2

Translate your text into patient-friendly language.

Once you have written a good first draft, check the readability statistics and evaluate according to the reading level of your audience. On Microsoft Word, these statistics pop up at the end of the spelling & grammar check feature. This gives you raw data about your document, including the number of words, the average number of words per sentence, and the Flesch-Kincaid Grade Level.

Next, examine your perfectly crafted sentences for opportunities to broaden the readability level. What reading level should you aim for? The U.S. literacy rate is seventh to eighth grade, which is 12 to 14 years old. Is that level sufficient, or should you aim lower? There are plenty of people on either side of average, and aiming more broadly can help you reach a bigger audience. We find that sixth grade often feels about right.

A patient flyer is likely to contain less medical jargon than, say, a visit-by-visit guide or a patient diary. Some documents will require more work.

What to assess when writing clinical study materials for patients:

Medical terms:

Are they known to your audience? For example, if your study is recruiting sciatica patients, your audience may know what sciatica means. So it stays, but you may want to add an explanation in plain language terms such as sciatica (pain in the back, hip, and outer side of the leg) to ensure clarity. If your study is the lung disease pneumonoultramicroscopicsilicovolcanoconiosis, there is no getting around that, either. It stays too, but a short explanation may be helpful to the reader. Also, consider if the use of abbreviations or acronyms will be understandable to your audience, and be sure to write them out the first time (e.g., hypertension [HTN]).

Look for things that are long:
  • Long words? Reduce the syllables.
  • Long sentences? Reduce the number of words.
  • Long paragraphs? Reduce the number of sentences.
Examples of common non-medical words that can be changed to increase readability:
  • Participate: take part
  • Reduce: lower
  • Confirm: make sure
  • Evaluate: find
  • Modify: change
  • Determine: find out
Examples of medical terms that can be changed or explained in a few words to improve readability:
  • Treatment-resistant: Treatment doesn’t work well
  • Effectiveness/efficacy: How well the [drug or procedure] works
  • Titrate: Change the dose of a medicine

It’s OK to retain a big word if it is necessary – just define it. Here is an example:

Shots will be given sequentially (one after the other).

A bullet list is a good way to rework a paragraph into distinct thoughts. Here is an example of changing some words and moving to a bullet list format. I have also added a line at the end that defines placebo:

Original paragraph:

Participants will be randomized (like flipping a coin) into two treatment arms. One arm will receive the study drug, and the other arm will receive a placebo.


People who take part in this study will be placed by chance (like flipping a coin) into 1 of 2 groups:

  • One group will receive the study drug
  • One group will receive a placebo

A placebo looks just like the study drug, but it contains no active medicine.

The revision takes up more space, but the information is communicated in a clearer way.

A note about numbers. The standard rule in writing is to spell out numbers one through nine and use Arabic numbers for 10 and above. Let’s agree that we can break that rule for ease of readability in our patient materials.

Step 3

Make sure you didn’t take it too far.

Before you consider your masterpiece finished, give it a fresh look. Did you reduce the reading level too severely? It’s possible to overdo it. As you read through, ask yourself:

Did I change or lose the meaning of a word?

For example, changing migraine to headache is probably too vague.

Did I go too far, perhaps alienating skilled readers and patients who are very knowledgeable about their indication?

For example, when writing clinical trial materials for a study enrolling patients who have already experienced a few rounds of chemotherapy similar to the study drug, the reader has a knowledge base and can most likely handle text with fewer explanations.

Did I leave out any important points?

For example:

Original sentence: It is possible the study drug will help patients recover from [disease being studied] more quickly.

Revision to reflect the protocol more completely: Study doctors will see if the study drug safely helps patients recover more quickly from [disease being studied] and see how well their bodies handle it.

Final thoughts

  1. When writing clinical trial materials, don’t let others sabotage your efforts. Your text is likely to go to others for their approval and/or edits. Let them know your text is written for patient-friendly readability and ask that they keep that in mind when making any changes.
  2. It’s up to you. Even though that reading level number can stay the same, go up, or go down as you make text changes, don’t give it too much control. It’s a guide. You be the judge of your text.
  3. Beginning with a first draft that isn’t at your audience’s reading level may seem like an unnecessary extra step. But give this method a try, and you may find that it actually streamlines the process and makes your final draft stronger.

Have you found ways to make your writing more patient-friendly? Please share your tips in the comment box near the bottom of this page. Also, our blog about using plain language when writing patient-facing clinical trial materials provides additional information to effectively reach the patient audience.

Updated: 28 JULY 2022

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