With the flu season upon us, an article published by the American Journal of Infection Control (AJIC) asks the question, “Is online influenza information readable?

The study was prompted by the fact that 70 percent of adults search the internet for health information, and the way articles are written influences readers’ perceptions.

The study analyzed content from the first 100 English language websites populated using the search term, “influenza”. Articles were vetted to check the relevancy of the content and analyzed using five different types of readability tests that evaluate characteristics, such as:

  • Sentence length
  • Grade level of writing
  • Number of letters in a word
  • Number of words in a sentence
  • Number of polysyllabic words

One of the tests even determined the minimum level of education needed to understand the content.  


Overall, the study finds that the readability tests classified 80 percent of the websites as difficult to read, as opposed to easy or average to read. Further analysis revealed that it is highly unlikely that online articles about influenza are being written at a readable level.

An analysis of the average readability scores for articles from .com, .org, or .gov websites showed that none of the scores met the recommended readability levels.

The authors conclude that information on the influenza virus isn’t being written at levels that can be widely comprehended by all audiences and recommend that educational efforts are directed toward ensuring that information is accessible by all.

Comprehensibility is especially important given the potential for a pandemic virus to spread rapidly, resulting in a need for people to access and understand vital health information. 

While the findings can’t be used to generalize other public health topics, the authors do point out that there is some evidence to show that other online health information is not written at a level that can be widely understood. 

Going Forward

This study highlights the need to ensure that people can access and understand information on influenza transmission, flu prevention and treatment, whatever their reading or education level. It also points to the fact that with the U.S. flu season upon us, many people may not fully understand the importance of the flu vaccine, how to prevent transmission and when to seek treatment. 

Healthcare personnel should be ready to provide useful flu information to patients at a range of facilities including pharmacies, physician offices and hospitals.

While there are many online sources of information for healthcare providers, the CDC influenza website should be an early port of call for anyone looking for guidance on the influenza virus and other vital health information.