A new study conducted by a team of researchers from the Denver Health Medical Center, Kaiser Permanente Colorado Institute for Health Research, the University of Colorado Denver, and other institutions, has found that low health literacy among patients with heart failure, a condition that requires self-management, was associated with higher death rates among those patients than among patients with adequate health literacy.
The study, Health Literacy and Outcomes Among Patients With Heart Failure, was published in the April 27, 2011 Issue of JAMA, the Journal of the American Medical Association.
In their introduction to the study report, lead author Pamela N. Peterson, M.D., M.S.P.H., of the Denver Health Medical Center, and her team explained that, “As defined by the Institute of Medicine, health literacy is ‘the degree to which individuals can obtain, process and understand basic health information and services needed to make appropriate health decisions.’ . . . Many US citizens and as many as 1 in 3 Medicare enrollees have low health literacy. The economic implications of low health literacy are substantial, in some estimates accounting for up to 5% of health care costs annually.”
“Heart failure,” the authors wrote, “is a common and complex chronic disease with high morbidity and mortality and thus has the attention of policy makers as a high-priority condition. Although patients with heart failure are frequently hospitalized, much care for heart failure is performed on a daily basis by individual patients outside of the hospital. This self-care requires integration and application of knowledge and skills. Therefore, an adequate level of health literacy is likely critical in ensuring patient compliance and proficiency in self-management.”
To measure the association between health literacy and outcomes among patients with heart failure, the researchers surveyed 2,156 patients with a history of heart failure, at Kaiser Permanente Colorado, an integrated managed care organization. The patients were surveyed by mail, and 1,547 responded (a 72% response rate). 1,494 of these patients were included in the study. Their health literacy was measured by three simple questions:
“(1) How often do you have someone help you read hospital materials?
(2) How often do you have problems learning about your medical condition because of difficulty reading hospital materials? and
(3) How confident are you filling out forms by yourself?
Patients assigned a value on a 5-point scale as their response to each question, with higher overall scores indicating lower health literacy.
Of the 1,494 patients included in the study, 262 (17.5%) had low health literacy. Patients with low health literacy were older, of lower socioeconomic status, less likely to have at least a high school education, and had higher rates of coexisting illnesses, including diabetes, hypertension, chronic pulmonary disease, and stroke.
The study patients were followed for a median of 1.2 years. During the follow-up period, 124 of the patients died, 17.6% among the patients with low health literacy, and 6.3% among those with adequate health literacy. Hospitalizations were also measured during follow-up, with 30.5% of the hospitalizations occurring among the low health literacy group, and 23.2% among those with adequate health literacy.
After adjusting for demographic variables, socioeconomic status, education, comorbid conditions, year of cohort entry, and left ventricular ejection fraction (a measure of how well the left ventricle of the heart pumps with each contraction), low health literacy was found to be independently associated with an increased risk of death from all causes. However, after the adjustments, low health literacy was not significantly associated with number of hospitalizations.
As to why low health literacy may correlate to higher risk of death, the authors suggest that low health literacy may affect “patients’ health actions outside of the health system, such as understanding and adhering to disease management and treatment strategies,” may lead to misunderstandings of medications, and may also cause patients to be reluctant to ask questions of doctors and “be less likely to participate in making decisions about [their own] clinical treatment.”
The authors recommend that routine assessment of health literacy may help to identify a greater number of patients at risk for adverse outcomes. They also suggest that doctors should be trained to “use appropriate teaching methods, reinforce education over time, and check for understanding in all patients with chronic disease.”
The researchers concluded, “This study identified a strong association between low health literacy and all-cause mortality in outpatients with heart failure. Although this study cannot demonstrate a causal relationship between health literacy and outcomes, it does justify further investigation of health literacy as a potentially modifiable risk factor for adverse outcomes in heart failure.”
“Interventions addressing literacy have been shown [by other studies to be] beneficial in improving quality of life and self-care and suggest possible benefits in reducing hospitalization and mortality among patients with heart failure, further supporting that health literacy may be a modifiable risk factor,” the authors wrote.
The study report is available from JAMA, the Journal of the American Medical Association, April 27, 2011 Issue.
For more information about heart disease and stroke, see our resource pages on Heart Diseases & Stroke
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