After adjusting for sociodemographics, health behaviors and clinical characteristics, patients with atrial fibrillation who had low health literacy were less likely to be aware of their diagnosis, according to an analysis of members from two large health insurance companies.

The researchers assessed health literacy with a three-item questionnaire. They also evaluated patients’ awareness of their atrial fibrillation diagnosis by asking them if a doctor or other healthcare professional had told them they had atrial fibrillation or atrial flutter.

Lead researcher Stephanie R. Reading, PhD, MPH, of Kaiser Permanente Southern California, and colleagues published their results online in the Journal of the American Heart Association on April 12.

“Being unaware of a medical diagnosis, such as [atrial fibrillation], can be problematic as it likely implies a lack of understanding of the health risks that are associated with the diagnosis and potential therapeutic options,” the researchers wrote. “Furthermore, there may be an increased risk of complications stemming from the primary diagnosis that could develop into secondary comorbidities and, in turn, lead to an increase in overall risk of morbidity, mortality, and cost of care.”

An estimated 5.2 million people in the U.S. were living with atrial fibrillation in 2010, according to the researchers, who added that 12.1 million people were projected to have atrial fibrillation by 2030.

This study included 12,517 patients from Kaiser Permanente Northern California and Southern California who were diagnosed with incident atrial fibrillation or atrial flutter between Jan. 1, 2006, and June 30, 2009.

The patients completed a 35-item health questionnaire between May 1, 2010, and Sept. 30, 2010, that included three questions pertaining to health literacy. The researchers defined health literacy as “the degree to which individuals have the capacity to obtain, process and understand basic health information and services needed to make appropriate health decisions.”

They found that 20.4 percent of patients had inadequate health literacy. Patients with inadequate health literacy were older, had lower socioeconomic status and had worse overall health. They were also more likely to be female and be unaware of their atrial fibrillation diagnosis and less likely to be non-Hispanic white or be married or with a partner.

In addition, 24.6 percent of patients with inadequate health literacy and 11.9 percent of patients with adequate health literacy were unaware of their atrial fibrillation diagnosis.

After controlling for sociodemographic characteristics such as age, sex, race/ethnicity, marital status and household income, inadequate health literacy was associated with less awareness of an atrial fibrillation diagnosis compared with adequate health literacy.

The results were similar when the researchers adjusted for health behavior characteristics such as physical activity, cigarette use, alcohol use and medication adherence; self-reported health status; and medical history.

The researchers mentioned a few limitations of the study, including its cross-sectional and observational design, which precluded them from assessing time-dependent factors or inferring a causal relationship between health literacy and lack of atrial fibrillation diagnosis awareness. They also noted that they used a self-reported questionnaire, which could lead to recall bias, social desirability bias and/or interviewer bias. In addition, they speculated that patients with inadequate health literacy might have been less likely to complete the questionnaire.

“Patients with inadequate health literacy were less likely to be aware of their [atrial fibrillation] diagnosis when compared with patients with adequate health literacy,” the researchers wrote. “This has broad implications for both patients and providers when managing care for patients with [atrial fibrillation]. Creating effective health literacy improvement strategies for patients with limited health literacy may be an effective solution for increasing awareness of [atrial fibrillation], its potential complications, and available therapeutic options.”