During the last week of May, WBEZ’s radio series Front & Center began airing a series about low literacy in the Great Lakes region. In an article on their Web site that accompanies the series, they run through a bulleted list of facts on the impact of low literacy. One of those bullets was: “Medication errors due to misread or misunderstood prescription labels cause up to 7,000 deaths each year.”

The inability to follow prescription instructions is a frequently used example to illustrate the challenges of low literacy. I’ve used it myself in material I’ve prepared for D.C. LEARNs and ProLiteracy. And it makes at least some logical sense. If prescription information is written at a level that is too difficult for people with low literacy to read, it’s not a stretch to assume that those people are more likely to make a mistake (and there is anecdotal evidence supporting this). But I wonder whether there is any hard data that actually shows how many people are directly harmed by people with low literacy misreading prescription labels.

The source for Front & Center‘s factoid above was derived from a 2005 American Medical Association publication that accompanied a White House Conference on Aging mini-conference on on health literacy and health disparities. Here is what that publication actually said:

All medications have the potential of causing harm as well as benefit, the incidence of adverse medication events increases with the number of medications. Medication errors are the most common medical mistakes – some as a result of misread or misunderstood prescription labels – causing up to 7,000 deaths each year and costing the health care system nearly $73 billion annually. Improving communications on medications can improve care, reduce errors, and save lives. (my emphasis)

The key word above is “some.” In other words, medication errors cause up to 7,ooo deaths annually, and the authors of this report think that some of those 7,000 are due to misread or misunderstood prescription labels. But even among that subset of the 7,000, it’s not stated how many misread or misunderstood prescription labels can be attributed to low literacy. Just because a label is misread or misunderstood, that doesn’t mean that low literacy was the cause. I have relatively high literacy and I misread things all the time.

I have passing familiarity with the literature on health literacy. I know there are studies on the relationship between low literacy and poor health, educational attainment and mortality rates, on the difficulties that people with low literacy have in understanding health information, or navigating the health care system, etc. What I’m specifically interested in is whether there is better data on the number of medication errors—and more importantly, the harm caused by those errors—that can clearly be attributed to low literacy adults misreading labels. Can anyone point me to a good source?