Not being able to read properly impairs people's ability to obtain critical information about their health and can dramatically shorten their lives, concludes a study in the Archives of Internal Medicine.
Older adults who cannot read and understand basic health information have a 50 per cent higher mortality rate over a five-year period than those with adequate reading skills, the study found.
"The excess number of deaths among people with low literacy was huge. The magnitude of this shocked us," said Dr. David Baker, lead author of the study and chief of general internal medicine at Northwestern University's Feinberg School of Medicine.
"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's team looked at 3,260 Medicare patients ages 65 and older in Cleveland, Tampa, Miami and San Antonio, starting in 1997. Researchers asked the participants about their race/ethnicity, education, income, health behaviors (smoking, alcohol consumption, exercise) and chronic medical conditions (diabetes, asthma, heart disease, etc.).
Participants completed a test of health literacy that included reading passages and health-related materials such as doctor appointment slips, hospital forms and pill bottles that required understanding numbers.
Their scores were ranked from zero to 100, with zero to 55 suggesting inadequate health literacy, 56 to 66 indicating marginal health literacy, and 67 to 100 signifying adequate health literacy. About 64 per cent of participants had adequate health literacy, 11.2 per cent had marginal health literacy and 24.5 per cent) had inadequate health literacy.
Then, in 2003, researchers looked at the 815 participants who had died during the study period, and found that they included:
- 39.4 per cent of those with inadequate health literacy
- 28.7 per cent of those with marginal health literacy
- 18.9 per cent of those with adequate health literacy
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.
"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 results show a 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."
Baker says that 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 his 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.
