A readability assessment of online stroke information

Patients and carers increasingly access the Internet as a source of health information. Poor health literacy is extremely common and frequently limits patient's comprehension of health care information literature. We aimed to assess the readability of online consumer-orientated stroke information using 2 validated readability measures.

The 100 highest Google ranked consumer-oriented stroke Web pages were assessed for reading difficulty using the Flesch-Kincaid and Simple Measure of Gobbledygook (SMOG) formulae.

None of the included Web pages complied with the current readability guidelines when readability was measured using the gold standard SMOG formula. Mean Flesch-Kincaid grade level was 10.4 (95% confidence interval [CI] 9.97-10.9) and mean SMOG grade 12.1 (95% CI 11.7-12.4). Over half of the Web pages were produced at graduate reading levels or above. Not-for-profit Web pages were significantly easier to read (P=.0006). The Flesch-Kincaid formula significantly underestimated reading difficulty, with a mean underestimation of 1.65 grades (95% CI 1.49-1.81), P<.0001.

Most consumer-orientated stroke information Web sites require major text revision to comply with readability guidelines and to be comprehensible to the average patient. The Flesch-Kincaid formula significantly underestimates reading difficulty, and SMOG should be used as the measure of choice.