Effects of an online plain language tool on health information quality: A randomised controlled trial
Authors: Ayre Julie , Bonner Carissa , Muscat Danielle M , Cvejic Erin , Mac Olivia , Mouwad Dana , Shepherd Heather L , Aslani Parisa , Dunn Adam G , McCaffery Kirsten J 
Published: April 2024

AbstractObjectiveComplex and ineffective health communication is a critical and persistent source of inequity in our health systems. This occurs despite repeated policy directives to provide patients and community with health information that is easy to understand and that applies health literacy principles. This study sought to evaluate the effectiveness of the Sydney Health Literacy Lab (SHeLL) Health Literacy Editor, an easy-to-use online plain language tool that supports health information providers to apply health literacy guidelines to written health information.DesignRandomised controlled trial with analysts blind to intervention group.SettingOnline study, AustraliaParticipants188 health information providers with no previous experience using the Health Literacy Editor (mean age 41.0 (SD=11.6); 154 female (85%)).InterventionParticipants were provided access to the Health Literacy Editor and a 30-minute online training program prior to editing three pre-specified health texts. The Health Literacy Editor gives objective, real-time, and fine-grained feedback on words and sentences. Control participants were asked to revise the texts using their own standard health information development processes.Main outcome measurePre-registered primary outcome was text grade reading score (using validated instrument, the Simple Measure of Gobbledygook). Secondary outcomes were use of complex language (% of the text) and passive voice (number of instances), subjective expert ratings (Patient Education Materials Assessment Tool), and acceptability ratings (System Usability Scale; Technology Acceptance Model).ResultsTexts revised in the intervention group had significantly improved grade reading scores relative to control (Mean Difference (MD)=2.48, 95% CI=1.84 to 3.12, p<0.001, d=0.99), lower text complexity (MD=6.86, 95% CI=4.99 to 8.74, p<0.001, d=0.95) and less passive voice (MD=0.95, 95% CI=0.4 to 1.5, p<0.001, d=0.53) in intention-to-treat analyses. Experts rated texts in the intervention group more favourably for word choice and style than those in the control group (MD=0.44, 95% CI=0.25 to 0.63, p<0.001, d=0.63), with no loss of meaning or content. Participants rated the Health Literacy Editor an acceptable product (71.0/100, SD=13.7) that was useful (3.8/5, SD=0.7) and easy to use (4.0/5, SD=0.6).Conclusions and relevanceThe Health Literacy Editor helped users simplify health information and apply health literacy guidelines to written text. It has high potential to improve development of health information for people who have low health literacy. As an online tool the Health Literacy Editor is also easy to access and implement at scale.Trial registrationACTRN12623000386639Summary boxSection 1: What is already known on this topic?Most health information is hard for people to understand, particularly those who are older, with less education, or who speak English as a second language.Systematic reviews show that texts that follow health literacy guidelines (e.g. use simpler words, shorter sentences and active voice) are easier for people to understand and recall.There are few automated tools that guide development of easy-to-understand written health information and none that have been rigorously evaluated in a randomised controlled trial.Section 2: What this study addsParticipants who used the Health Literacy Editor were able to more effectively simplify health information compared to participants in the control group.On average participants in the intervention group produced texts suitable for a person with almost 2.5 fewer years of school education compared to those in the control group. Similar patterns were observed for complex language and passive voice.The Health Literacy Editor is an effective tool to support development of written health information that adheres to plain language principles. It can be used in clinical and non-clinical settings and implemented at scale.