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  • Olivia Mac

Should we be writing health information to target a grade 8 reading level?

Many studies have shown health information is often written at a level that is too complex for most people. By health information, we are referring to basically any form of written health material. Some examples include webpages, pamphlets provided by your doctor or medicine instructions.


During the COVID-19 pandemic we looked at how easy official public health information was to read, understand and use. We found that most official online information was written at around a grade 12 reading level.


But what does this mean?

Assessing the grade reading level of text is a quick and easy way of estimating the text difficulty. However, it is far from perfect, because it is based on factors like the number of syllables per word or the number of words per sentences. This means that there are a lot of other things that it does not consider. For example, it does not look at factors like:

  • the use of images or animations

  • bullet points

  • white space

  • the readers prior experience (how familiar they are with the topic)


Some guidelines recommend that health information should be written at a grade 8 reading level. Researchers often assess whether information on certain topics meet these guidelines. This is what we did here. Developers of health information may also assess the grade reading level to help them revise and simplify their text. Developers can use tools like the SHeLL editor which not only calculates the grade reading level, but it also flags complex language, acronyms and words that are uncommon in English.


Throughout my PhD, we started to notice that there was very little evidence to support these guidelines. We wanted to find out whether information written at a grade 8 reading level actually resulted in better knowledge scores. Do people find it easier to read?


So, what did we do?

To address this research gap, we ran an online experiment with 2235 participants aged over 18 and living in Australia. We randomly assigned participants to one of four groups. We then asked them to read information about two conditions (sciatica and knee osteoarthritis) written at one of four grade reading levels (8, 10, 12 and 14). After reading the information, we measured participants’ knowledge, how easy they found it to read and whether they found it useful and trustworthy.

We found no difference in total knowledge scores!

Our results showed that information written at lower grade reading levels did not result in higher knowledge. Most people found all texts easy to read, useful and trustworthy. We are currently in the process of unpacking these results. It may be that other aspects of information are more important, and we should be taking grade reading level with a grain of salt. We are also interested in exploring whether the results would be different amongst people with lower levels of literacy or education.


Watch this space as we try to address these unanswered questions! Check out our webpage to find out more about this project and other research projects we’re doing at the Sydney Health Literacy Lab!




Olivia Mac is a PhD candidate at the Sydney Health Literacy Lab within the University of Sydney School of Public Health. Her research is focussed on the accessibility of health information, particularly how to optimise the assessment of written health information.

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