Most adults misunderstand standard warnings on prescriptions

Simple, concise language on warning labels of prescription medicine bottles is easier for patients to understand than the standard wording commonly used, according to the study. And the fewer warnings on a label, the more likely a patient will actually pay attention to them.

For the study, Northwestern researchers and colleagues worked with patients and nationally renowned graphic designers to simplify and redesign the confusing language and icons of standard warning labels. Many of them have been used for decades without any evidence to show patients comprehend them, or even if they are true.

"The study shows the value of a clear message," said Michael Wolf, associate professor of medicine and of learning sciences at Feinberg and lead author of the study. "A lot of the current warnings were phrased very abstractly and were confusing. For example, we changed 'For external use only' to 'Use only on your skin.' We moved from the intangible to the concise."

Many of these label warnings are critical for patients to take their medications safely. But previous research by Wolf and colleagues found more than half of adults misunderstand common standard drug warnings, putting them at risk for using the medicine incorrectly or even having a life-threatening event.

As a result of the new findings, Wolf and colleagues from Emory, Harvard and Louisiana State universities are working with the U.S. Pharmacopeia on a drug labeling task force to help overhaul the content and use of these labels.

The study also found that newly designed icons improved understanding for patients with low health literacy, a group at greatest risk for misinterpreting instructions and misusing medications. The paper was published in a recent issue of Archives of Internal Medicine.

The graphic designers worked with the researchers and patients to capture their mental images of what each message means. "A current and widely used icon of a pregnant woman resembles an olive," Wolf said. "For most people that probably doesn't convey pregnancy. The new design of a silhouette of a pregnant woman with a bump on her stomach was more easily recognizable to patients."

The design team included Deborah Adler, the co-creator of Target Corp.'s highly innovative and successful prescription bottle and labeling system called the ClearRx system, and Milton Glaser, a co-founder of New York Magazine who is known for creating the "I love NY" logo and a concert poster for Bob Dylan.

Because the study found that patients ignore too many warnings on the bottle, Wolf recommends a limit of two. Those should include the most important few, and these should have evidence confirming their necessity.

Several warning labels found on pill bottles today were created years ago without a scientific base, Wolf said. "There may not be a reason to use many of these," he noted. "And with such limited real estate on a pill bottle, the fewer the better. Our study supports that."

"We need to out which are the most important warnings and only put those on the label. Otherwise you risk the message never reaching the patient," Wolf said. "The more warnings you put on a label, the more you distract them from essential instructions and precautions that ensure they safely use the medicine."

The study included 500 adult patients from two academic and two community health clinics in Chicago and Shreveport, La. The patients were tested on their interpretation of nine drug warning labels that were 1) current standard drug warning labels on prescription containers; 2) drug warnings with text rewritten in simplified language or 3) labels with simplified language and icons developed with patient feedback. The patients reading standard labels had an 80 percent rate of correct interpretations, simplified text was 91 percent and simplified text with new icons was 92 percent.

"Our findings underscore the importance of including patients in the process and using meaningful, plain language to support their understanding and proper use of their medicine," Wolf said.

The study was funded by Target Corp. and the Agency for Healthcare Research and Quality.