Low literacy can shorten life

Jul 24 2007

Not being able to read doesn't just make it harder to navigate each day. Low literacy impairs people's ability to obtain critical information about their health and can dramatically shorten their lives.

A new study from Northwestern University's Feinberg School of Medicine shows that older people with inadequate health literacy had a 50 percent higher mortality rate over five years than people with adequate reading skills. Inadequate or low health literacy is defined as the inability to read and comprehend basic health-related materials such as prescription bottles, doctor appointment slips and hospital forms.

Low health literacy was the top predictor of mortality after smoking, also surpassing income and years of education, the study showed. Most of the difference in mortality among people with inadequate literacy was due to higher rates of death from cardiovascular disease.

"It's a matter of life or death," said David Baker, M.D., lead author of the study and chief of general internal medicine at the Feinberg School. "The excess number of deaths among people with low literacy was huge. The magnitude of this shocked us."

"When patients can't read, they are not able to do the things necessary to stay healthy," Baker noted. "They don't know how to take their medications correctly, they don't understand when to seek medical care, and they don't know how to care for their diseases." Baker thinks this is why they are much more likely to die.

The study will be published in Archives of Internal Medicine July 23.

More than 75 million adults in the United States have only basic or below basic health literacy, according to the 2003 National Assessment of Adult Literacy.

"There is a certain minimum set of reading skills that are required to be able to do the things that you're expected to do as a patient," Baker said. "And if someone is below that level, bad things are going to happen."

The Northwestern study began in 1997 when research assistants interviewed 3,260 Medicare patients ages 65 and older in Cleveland, Tampa, Miami and San Antonio. Researchers asked about participants' race/ethnicity, education, income, health behaviors (smoking, alcohol consumption, exercise) and chronic medical conditions (diabetes, asthma, arthritis, hypertension, heart disease, cancer, depression).

Participants completed a test of health literacy that included reading passages and health-related materials such as pill bottles that required understanding numbers. Then, in 2003, researchers determined which participants had died during the six years after being interviewed by matching their names against the National Death Index.

The results show a dramatic need for health care providers to find better ways to educate low literacy patients about their health.

"We need to use plain language," Baker said. "We're not talking about dumbing down material. We're talking about using simple language the average person would understand." He'd like to vanquish medical jargon from doctor's language and educational health materials. One example is saying "sugar" instead of "glucose" when discussing diabetes.

Many concepts also are easier to understand through graphics and multimedia than words. "If one picture is worth a thousand words, maybe one movie is worth 10 pictures," Baker said. "So, if you're going to explain to somebody with a condition called heart failure that their heart is not pumping hard enough, a moving image may show this much more clearly than words or a still image."

Often, low literacy patients need multiple repetitions to fully understand information.

"We need to learn to repeat the material or instructions until someone is able to repeat it back to you in his own words or answer questions about the material," Baker said.

Baker and colleagues are currently designing simpler health education materials for patients about colorectal cancer, asthma and diabetes. They are working directly with patients to find the best words and methods to explain health information.

Much more work is needed, Baker said. "In asthma and diabetes, now we actually know what words to use to be understood. But there are hundreds of other topics we haven't addressed. In those, I think we're still doing a poor job."

Changes will benefit all patients, particularly those in late middle age and older. Mental functions begin to decline in the 30's and reading comprehension is much lower among the elderly. As our population ages, Baker said, the problem of inadequate health literacy and the need to improve methods of health education and communication are certain to increase.