[Comprehensibility of online-based patient education material in ophthalmology]

Investigations have shown that the internet as a source of information in medical issues is increasing in importance. For most patients information delivered or supported by hospitals and universities is considered to be the most reliable, however, the comprehensibility of available information is often considered to be wanting. Comprehensibility scores are formulae allowing a quantitative value for the readability of a document to be calculated.

The purpose of this study was to assess data by analyzing the comprehensibility of medical information published on the websites of departments for ophthalmology of German university hospitals. We investigated and analyzed medical information dealing with three eye diseases with potentially severe irreversible damage.

The websites of 32 departments for ophthalmology of German university hospitals were investigated. Information regarding cataracts, glaucoma and retinal detachment (amotio retinae) were identified and analyzed. All information was systematically analyzed regarding comprehensibility by using the analysis program Text-Lab ( http://www.text-lab.de ) by calculation of five readability scores: the Hohenheim comprehensibility index (HVI), the Amstad index, the simple measure of gobbledygook (G-SMOG) index, the Vienna non-fictional text formula (W-STX) and the readability index (LIX).

In 59 cases (61.46 %) useful text information from the homepage of the institutions could be detected and analyzed. On average the comprehensibility of the information was identified as being poor (HVI 7.91 ± 3.94, Amstad index 35.45 ± 11.85, Vienna formula 11.19 ± 1.93, G‑SMOG 9.77 ± 1.42 and the LIX 54.53 ± 6.67).

In most of the cases patient information material was written far above the literacy level of the average population. It must be assumed that the presented information is difficult to read for the majority of the patients. A critical evaluation of accessible information material seems to be desirable and available texts should be amended.