Literacy affects health through a combination of both direct and especially indirect means. Let us first consider the direct effects.

As indicated earlier, a large proportion of Canadian adults have difficulty understanding the directions on medication labels. Close to half have difficulty understanding complex materials. Thus it is hardly surprising that failure to understand information about medications, health practices, and safety risks can result in health problems.

There is limited documentation in the published research literature about the direct effects of literacy on health. But the survey and case studies carried out as part of the OPHA research study identified numerous examples of health problems, often severe enough to require hospitalization, directly arising from literacy difficulties. Since then, the National Literacy and Health Program of the Canadian Public Health Association (CPHA), the Ontario Literacy Coalition (OLC), the Manitoba research effort, and a variety of literacy and health groups across Canada have identified numerous other instances. Examples follow:

Incorrect use of medications. Nearly half the respondents to the survey of the OPHA research study provided illustrations of errors in the use of over-the-counter and prescription medications as a result of literacy difficulties. CPHA says that “there are hundreds of stories of people who failed to respond to prescription drug treatment because they took the incorrect dose at the wrong time of day.” The OLC cites the following example of a woman with diabetes:

“...She needs to follow a restricted diet and take several medications prescribed by her family physician at regular intervals each day. But [she] is unable to read food labels or the instructions that come with her prescription medicines. [Her] literacy problems are a hazard to her health!”