It appears that seniors who are unable to read and understand basic health information have raised mortality rates over a five-year period, compared to people whose health literacy is adequate, according to an article in Archives of Internal Medicine (a JAMA/Archive journal), July 23 issue.

The more years of school a person has completed the longer he/she is expected to live, states the article. Most likely, this is because the better a person’s education is, the higher his/her income is likely to be, as well as access to health insurance, decent housing and food.

The authors write “Another possible mechanism by which education could exert a direct effect on health is reading fluency. The number of years of school completed is strongly associated with reading fluency. As a result, individuals with more education tend to have a better capacity to obtain, process and understand basic health information and services needed to make appropriate health decisions: i.e., they have higher levels of health literacy.”

David W. Baker, M.D., M.P.H., Northwestern University Feinberg School of Medicine, Chicago, and team, interviewed 3,260 medicare patients in 1997 – they were all over 65 and lived in four metropolitan areas. The interviewees were asked questions about health and demographics. They also had to complete a health literacy test involving two reading comprehension texts and four mathematical items. A score of 0-55 would indicate inadequate health literacy, 56-66 would indicate marginal health literacy, while 67-100 meant the participant had adequate health literacy (maximum score 100, minimum 0).

The results were as follows:

  • 64.2 percent (2,094) had adequate health literacy
  • 11.2 percent (366) had marginal health literacy
  • 24.5 percent (800) had inadequate health literacy

By using the National Death Index, the researchers cross checked how many of the participants had died by the end of 2003 (67.8 months later):

  • 25% (815) had died out of the 3,260 total
  • 39.4% of those with inadequate health literacy had died
  • 28.7% of those with marginal health literacy had died
  • 18.9% of those with adequate health literacy had died

The results indicate that a person with inadequate health literacy has a higher risk of mortality. In this study the researchers had factored in such variables as demographics, socioeconomic status and health behaviors.

11.7% of all participants died of cardiovascular disease. 19.3% of those with inadequate health literacy died of heart disease – the figure for those with marginal health literacy was 16.7%, and 7.9% for those with adequate health literacy.

The authors stated that “Inadequate health literacy is associated with less knowledge of chronic disease and worse self-management skills for patients with hypertension, diabetes mellitus, asthma and heart failure. Use of cancer screening and vaccinations are also lower among people with inadequate health literacy. Thus, the association between health literacy and adverse health outcomes probably occurs as the result of a wide variety of pathways that have a cumulative effect.”

Studies have indicated that patients with diabetes and heart failure who have inadequate health literacy can have better outcomes by using targeted intervention.

The authors conclude that “Most people will have many acute and chronic medical conditions during their life and face many situations in which they must make health and health care choices and decisions. As a result of these myriad demands placed on patients today, widespread improvements in health and health care communication will likely be necessary to reduce the association between health literacy and mortality.”

Archives of Internal Medicine
2007;167(14):1503-1509.

Written by Christian Nordqvist