Readability assessment of online ophthalmic patient information

Matthew R Edmunds, Robert J Barry, Alastair K Denniston

Research output: Contribution to journalArticlepeer-review

53 Citations (Scopus)


IMPORTANCE: Patients increasingly use the Internet to access information related to their disease, but poor health literacy is known to impact negatively on medical outcomes. Multiple agencies have recommended that patient-oriented literature be written at a fourth- to sixth-grade (9-12 years of age) reading level to assist understanding. The readability of online patient-oriented materials related to ophthalmic diagnoses is not yet known.

OBJECTIVE: To assess the readability of online literature specifically for a range of ophthalmic conditions.

DESIGN AND SETTING: Body text of the top 10 patient-oriented websites for 16 different ophthalmic diagnoses, covering the full range of ophthalmic subspecialties, was analyzed for readability, source (United Kingdom vs non-United Kingdom, not for profit vs commercial), and appropriateness for sight-impaired readers.

MAIN OUTCOMES AND MEASURES: Four validated readability formulas were used: Flesch Reading Ease Score (FRES), Flesch-Kincaid Grade Level (FKGL), Simple Measure of Gobbledygook (SMOG), and Gunning Fog Index (GFOG). Data were compared with the Mann-Whitney test (for 2 groups) and Kruskal-Wallis test (for more than 2 groups) and correlation was assessed by the Spearman r.

RESULTS: None of the 160 webpages had readability scores within published guidelines, with 83% assessed as being of "difficult" readability. Not-for-profit webpages were of significantly greater length than commercial webpages (P = .02) and UK-based webpages had slightly superior readability scores compared with those of non-UK webpages (P = .004 to P < .001, depending on the readability formula used). Of all webpages evaluated, only 34% included facility to adjust text size to assist visually impaired readers.

CONCLUSIONS AND RELEVANCE: To our knowledge, this is the first study to assess readability of patient-focused webpages specifically for a range of ophthalmic diagnoses. In keeping with previous studies in other medical conditions, we determined that readability scores were inferior to those recommended, irrespective of the measure used. Although readability is only one aspect of how well a patient-oriented webpage may be comprehended, we recommend the use of readability scoring when producing such resources in the future. Minimum readability policies and inclusion of facilities within webpages to maximize viewing potential for visually impaired readers are important to ensure that online ophthalmic patient information is accessible to the broadest audience possible.

Original languageEnglish
Pages (from-to)1610-6
Number of pages7
JournalJAMA Ophthalmology
Issue number12
Publication statusPublished - Dec 2013


  • Comprehension
  • Computer-Assisted Instruction
  • Databases, Factual
  • Educational Measurement
  • Eye Diseases
  • Guidelines as Topic
  • Health Literacy
  • Health Policy
  • Humans
  • Internet
  • Patient Education as Topic
  • Reading
  • Teaching Materials
  • United States
  • United States Dept. of Health and Human Services


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