5b. Can Health Communication Campaigns Increase Health Inequities? Overcoming the Knowledge Gap Hypothesis  

One of the persistent myths in population health practice (although it’s not as prevalent as it once was) is the “if you tell them, they will know” assumption that public health problems can be “solved” through education alone.¹ This assumption is contradicted by a number of studies indicating that knowledge is not equally distributed across the population: individuals with more formal education tend to learn about, and be aware of, preventive health practices more than people with less formal education. Moreover, people with higher levels of income have the resources to act on current recommendations about the actions needed to promote and maintain good health (e.g., purchasing a fitness club membership) than lower-income people.²

These findings were formally incorporated into the knowledge gap hypothesis, which maintains that increasing the volume of information from a health communication campaign is more likely to benefit higher socio-economic status (SES) groups than their lower SES counterparts.³ Over time, increasing information about a health issue, such as the health benefits of eating 5–10 servings of fresh fruits and vegetables a day, could serve to exacerbate, rather than reduce, health inequities, as higher SES people are better able to afford the higher cost of fresh produce.

The potential for SES-based knowledge gaps is evident when one studies the disparity in access to the Internet between more- and less-developed countries. As illustrated in the following graph, between 1997 and 2007, there was a vast difference in Internet users per 100 inhabitants in developed vs non-developed nations. Given that this was the time period when the Internet was increasingly used as a key vehicle for health communication campaigns, it could, therefore, be argued that Internet-based health communication may have inadvertently increased health inequities at a global level.

 

ITU World Telecommunication. (2008, July 15). Internet users per 100 inhaibitants. Retrieved from http://www.itu.int/ITU-D/ict/statistics/ict/index.html

 

Subsequent studies have found that knowledge gaps, while present, are not intractable. The impact of knowledge gaps induced by communication campaigns can be alleviated through community mobilization, tailored messages for low SES groups, and access to additional resources and supports.⁴ As was noted earlier, this emphasizes the importance of supplementing communication campaigns with complementary strategies to address social, economic, and environmental barriers to change.⁵