Research Shows Low Health Literacy Linked to Risk of Death, Emergency Care, More Frequent Hospitalizations

RESEARCH TRIANGLE PARK, N.C.—Low health literacy in older Americans is linked to poorer health status and a higher risk of death, according to a new evidence review by researchers at RTI International-University of North Carolina Evidence-based Practice Center.

Seventy-seven million English-speaking adults in the United States have limited health literacy, making it difficult for them to understand and use basic health information. Rates of limited health literacy are higher among seniors, minorities, lower-income Americans and those with less than a high school education.

The evidence review, published in the July 19th issue of Annals of Internal Medicine, is an update of a 2004 review of the literature based on 96 new studies published in English. The review was supported by the U.S. Department of Health and Human Services' Agency for Healthcare Research and Quality.

The researchers found an association between low health literacy in Americans age 18 and older and poorer use of health care services, including more frequent use of emergency rooms and more hospital admissions, a lower likelihood of getting flu shots and of understanding medical labels and instructions, and a greater likelihood of taking medicines incorrectly compared to adults with higher health literacy. Additionally, the review found evidence linking low health literacy among adult women and underuse of mammograms.

"Our updated review should enhance the public's awareness that low health literacy can play a substantial role in the interrelationship among patient characteristics, use of health care services, and resulting health outcomes," said Nancy Berkman, Ph.D., a senior research analyst at RTI International and the study's lead author. "Finding ways to reduce the effects of low health literacy on health outcomes warrants the attention of policymakers, clinicians, and other stakeholders."

The review also showed a link between low health literacy and poorer health outcomes including poorer health status and higher mortality rates among elderly persons.

Furthermore, evidence from a small but growing body of studies suggests that differences in health literacy level are related to racial and ethnic disparities, such as health status and flu shot rates among seniors, enrollment of children in health insurance programs, and taking medications as instructed by a health care professional.

"Evidence is emerging that lower health literacy at least partially explains racial disparities in health outcomes," Berkman said. "This evidence was demonstrated across several studies we looked at, each one measuring a different outcome."

The evidence review was conducted by AHRQ's RTI-UNC Evidence-based Practice Center, a collaboration between RTI and the five health professions schools and the Cecil G. Sheps Center for Health Services Research at UNC.