October 4, 2005 | Research

Health Literacy Linked to Poor Health

CHICAGO --- Elderly individuals with poor health literacy have more physical and mental health problems than those with adequate health literacy, according to a study published in the Sept. 26 issue of Archives of Internal Medicine.

The study, led by Michael S. Wolf of Northwestern University Feinberg School of Medicine, found that even though older adults with lower health literacy were more likely to have never smoked and to have abstained from alcohol than those with adequate health literacy, those with poor health literacy were in worse emotional and physical condition than their health-literate counterparts.

The Institute of Medicine reports that 48 percent of adults in the U.S. have inadequate health literacy, defined as the ability to obtain, process and understand basic information and services needed to make appropriate decisions regarding health, according to background information in the article. Besides basic reading skills, individuals need to be able to read and understand numerical information such as that on prescription bottles and be able to read and interpret document information such as appointment slips.

Wolf, an assistant professor of medicine at the Feinberg School, and colleagues at Northwestern and Emory University used data from a survey of over 2,900 Medicare participants -- average age 71 years -- in Cleveland, Houston, Tampa and Fort Lauderdale-Miami. They conducted interviews to determine individuals’ physical and mental health status, including medical history and alcohol and tobacco use.

Approximately one third of those surveyed had marginal (11 percent) or inadequate (22 percent) health literacy.

Individuals with inadequate health literacy had significantly higher rates of certain chronic conditions, including high blood pressure, diabetes mellitus, heart failure and arthritis.

Individuals with inadequate health literacy were more likely to report limitations related to health, including activities of daily living and pain that interfered “quite a bit” or “extremely” with normal work activity.

“The magnitude of these association were large and clinically important,” the researchers said.

Previous studies have suggested that inadequate health literacy is linked to worse knowledge of proper health behaviors and lower adherence to medical instructions; that despite access to health care the quality of medical encounters may be compromised when health care providers do not communicate at a level that is understood; and that patient education materials may be too complex or written at too high a level to be helpful.

“Over time, these factors could contribute to the worse health status seen among the older patients with low health literacy in this study,” the authors suggested.

“Although the causal pathways between low health literacy and disease-specific health outcomes remain unclear, this study provides further evidence of the likelihood that inadequate health literacy detrimentally affects health,” the authors conclude.

To develop appropriate and responsive interventions, the researchers recommend that future studies discern how adults with lower health literacy recognize health issues and identify barriers to seeking out appropriate health care services. In addition, interventions are needed that can help physicians and other health care professionals recognize and address the special needs of patients with limited health literacy.

Wolf’s co-researchers on the study were David W. Baker, M.D., associate professor of medicine, Feinberg School, and Julie A. Gazmararian, Emory Center on Health Outcomes and Quality, Emory University, Atlanta. Wolf and Baker are researchers in the division of general medicine and the Institute for Healthcare Studies at Feinberg and affiliated with The Robert H. Lurie Comprehensive Cancer Center of Northwestern University.

Wolf is supported by career development award 1 K01 EH000067-01 from the Centers for Disease Control and Prevention, Atlanta.