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Most health information does not meet the health literacy needs of our communities. Writing health information in plain language is time-consuming but the release of tools like ChatGPT may make it easier to produce reliable plain language health information.


To investigate the capacity for ChatGPT to produce plain language versions of health texts.


Observational study of 26 health texts from reputable websites.


ChatGPT was prompted to ‘rewrite the text for people with low literacy’. Researchers captured three revised versions of each original text.

Main Measures

Objective health literacy assessment, including Simple Measure of Gobbledygook (SMOG), proportion of the text that contains complex language (%), number of instances of passive voice and subjective ratings of key messages retained (%).

Key Results

On average, original texts were written at grade 12.8 (SD = 2.2) and revised to grade 11.0 (SD = 1.2), p < 0.001. Original texts were on average 22.8% complex (SD = 7.5%) compared to 14.4% (SD = 5.6%) in revised texts, p < 0.001. Original texts had on average 4.7 instances (SD = 3.2) of passive text compared to 1.7 (SD = 1.2) in revised texts, p < 0.001. On average 80% of key messages were retained (SD = 15.0). The more complex original texts showed more improvements than less complex original texts. For example, when original texts were ≥ grade 13, revised versions improved by an average 3.3 grades (SD = 2.2), p < 0.001. Simpler original texts (< grade 11) improved by an average 0.5 grades (SD = 1.4), p < 0.001.


This study used multiple objective assessments of health literacy to demonstrate that ChatGPT can simplify health information while retaining most key messages. However, the revised texts typically did not meet health literacy targets for grade reading score, and improvements were marginal for texts that were already relatively simple.

In recent years, health literacy has come to the forefront of public health research and practice, with persistent calls to provide health information that is easy to access and understand.12 Studies consistently report that most health information does not address the health literacy needs of our communities, particularly those who are older, with lower education and have less fluency in a community’s dominant language.3,4,5,6 This includes information developed by government, health services and non-government organisations.78

Addressing this issue is challenging given the vast amount of health information available online. Currently, writing in plain language requires a health information provider to manually implement advice from health literacy guidelines and checklists.9,10,11,12 This is a process that demands considerable expertise and time. Though there are tools for objectively assessing the health literacy of health information and automating text-simplification,13,14,15 revisions are still largely carried out by humans.

Recent advances in large language models present new opportunities that might transform our ability to develop plain language health information at scale. For example, in November 2022, OpenAI publicly released ChatGPT, a large language model that has been trained on a large database of text data to produce plausible, contextually appropriate and human-like responses to prompts—typically questions or requests to produce writing meeting certain constraints. Large language models do not synthesise or evaluate evidence, but rather they predict what should come next in a piece of text by learning from large volumes of training data.16 ChatGPT is also capable of adapting text to different writing styles and audiences, has a simple user interface that does not require software or programming expertise, and is freely available.

There is limited evidence showing that ChatGPT can produce information that adheres to health literacy guidelines. For example, one study has shown that ChatGPT prompts can produce patient letters that are written at 9th grade reading level,17 and rated ChatGPT output describing patient postoperative instructions as adequately understandable, actionable and generally complete.18 However, there is substantial room for improvement, both in terms of optimising the ChatGPT prompts and employing more comprehensive assessment of plain language. Other studies have found that ChatGPT outputs in health domains were generally correct and complete, with low potential for harm, though the complexity of the language was not assessed.1920 Several studies have also identified a reasonable level of accuracy in ChatGPT output that responds to health questions.21,22,23,24

This study sought to investigate the capacity for ChatGPT (GPT-3.5) to produce plain language versions of health texts across a range of health topics. To our knowledge, no studies have evaluated the appropriateness of plain language health information generated by ChatGPT using multiple objective assessments.


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Author Descriptions

Sydney Health Literacy Lab, Sydney School of Public Health, Faculty of Medicine and Health, The University of Sydney, Rm 128C Edward Ford Building, Sydney, NSW, Australia
Julie Ayre PhD, Olivia Mac MPH, Kirsten McCaffery PhD, Brad R. McKay FRACGP, MPH, Mingyi Liu MPH, Yi Shi MPH & Atria Rezwan BPsychSc(Hons)

Discipline of Biomedical Informatics and Digital Health, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
Adam G. Dunn PhD


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