How much do you know about your own health and medical conditions? A new study shows that patients who are less "health literate" than others have a greater chance not only of being hospitalized, but also of dying from any cause.

According to the study, health literacy is defined by the Institute of Medicine as "the degree to which individuals can obtain, process and understand basic health information and services needed to make appropriate health decisions." The authors wanted to see if there was a connection between health literacy, measured by three simple questions, and a person’s health outcome (how likely they were to be hospitalized in the future, and to die).

They studied 1,500 people who had had heart failure in the past, since rebounding from and living with this condition requires a fair amount of knowledge and understanding of the condition.

To measure participants’ health literacy, they asked them the following three questions: "How often do you have someone help you read hospital materials?" "How often do you have problems learning about your medical condition because of difficulty reading hospital materials?" "How confident are you filling out forms by yourself?" The participants rated their answers on a five-point scale, so that the higher their final score, the less health literate they were.

Of the total pool of patients, 17.5% had low health literacy. These people were less likely to have a high school education, more likely to be of lower socioeconomic status, and older.

During the study’s 1.2 year follow up period, 124 patients died of various causes. The low health literacy group had more total deaths (18%) than people in the "adequate" health literacy group (6%), which represents a three-fold greater likelihood of dying. People with low health literacy were slightly more likely to be hospitalized for any reason than people with adequate literacy (31% vs. 23%), but the results were not statistically significant (meaning that the difference could have simply been due to chance).

The results held true even after other factors like education, socioeconomic status, and having a secondary health problem were taken out of the equation.

If doctors would begin to assess their patients’ health literacy routinely, the authors argue, this could be a simple but powerful tool to identify at-risk patients. Using a quick three-question test like the one used here could be a real benefit to the doctor-patient relationship: patients with low health literacy may be less likely to ask important questions about their conditions, so knowing who is at risk could prompt doctors to explain things in greater depth, and ask if the patient understands everything being communicated. The authors point out that "health literacy is not a fixed trait but rather a state," which can be changed; doing so might also change health outcomes in significant ways.

The study was led by researchers at Denver Health Medical Center, and published in the April 27, 2011 issue of The Journal of the American Medical Association.