Patients increasingly use the internet to access information related to their disease. Health literacy is known to be poor, with multiple agencies (e.g. US Department of Health and Human Services [USDHHS]) recommending that patient-orientated literature be written at a fourth- to sixth-grade (9-12 years of age) reading level to assist understanding. We aimed to assess readability of online literature specifically for thyroid eye disease (TED).

Readability of the content of the 50 highest ranked TED patient-orientated online resources was analysed. Webpages were identified using the Google search term ‘thyroid eye disease’. Extraneous text (e.g. hyperlinks, affiliations, disclaimers) was removed. Relevant text proceeded to readability analysis using three validated measures: Flesch Reading Ease Score (FRES), Flesch-Kincaid Grade Level (FKGL) and Simple Measure of Gobbledygook (SMOG). Readability was categorised by USDHHS standards.

The majority (58%) of TED online patient literature were of UK origin. Most (46%) were from not-for-profit websites and 24% from commercial websites. Mean webpage word count was 1191 (SD 733, range 195 – 3867). Mean FRES was 45 (SD 8.9, range 24–64), mean FKGL 12 (SD 1.8, range 7.2-17) and mean SMOG 13 (SD 1.4, range 9.6–17), each equivalent to reading level of >12th grade and “difficult” on the USDHHS classification. There was no significant difference with country of origin or website type.

Readability scores for online TED patient-orientated materials are inferior to those recommended. Although readability is only one aspect of comprehension, screening TED online material, and subsequent revision, is crucial to increase patient knowledge, satisfaction and compliance.