ScienceDaily (July 26, 2007) — Not being able to read doesn’t just make it harder to navigate each day. Low literacy impairs people’s ability to obtain critical information about their health and can dramatically shorten their lives.

A study from Northwestern University’s Feinberg School of Medicine shows that older people with inadequate health literacy had a 50 percent higher mortality rate over five years than people with adequate reading skills. Inadequate or low health literacy is defined as the inability to read and comprehend basic health-related materials such as prescription bottles, doctor appointment slips and hospital forms.

Low health literacy was the top predictor of mortality after smoking, also surpassing income and years of education, the study showed. Most of the difference in mortality among people with inadequate literacy was due to higher rates of death from cardiovascular disease.

“It’s a matter of life or death,” said David Baker, M.D., lead author of the study and chief of general internal medicine at the Feinberg School. “The excess number of deaths among people with low literacy was huge. The magnitude of this shocked us.”