Fig 1.

The readability of all the articles as measured individually by the 10 readability scales. The 9 other readability scales include the CLI, NDC, FKGL, FORCAST Formula, Fry Graph, GFI, NFC, RRE, and SMOG; and their grade level is measured on the left y-axis (Grade Level). The FRE score is measured on the right y-axis (FRE Score). The yellow area corresponds to the grade level recommendations from the National Institutes of Health and the AMA. FRE scores of 0–30 indicate the patient education resources are very difficult, 30–50 are difficult, 50–60 are fairly difficult, 60–70 are standard, 70–80 are fairly easy, 80–90 are easy, and 90–100 are very easy.