Friday, September 4, 2009

Improving your understanding of health risks

When there is a plane crash in the news, my mother-in-law, who dislikes flying anywhere but has driven coast-to-coast many times, says that she will never get on a plane again. But according to the National Center for Health Statistics, the odds of being in a serious car accident during your lifetime are a mere 1 in 100, while the odds of being in an accident involving a plane are 1 in 20,000. (And my mother-in-law did much of her driving in the days before child seat belt laws.)

Just as making rational decisions about traveling requires knowing the type and magnitude of risks involved, making informed decisions about one’s health requires understanding the risks associated with health conditions and treatments. In a 2007 study in the Annals of Internal Medicine , researchers examined how providing patients with an educational primer about risk improved their skills in interpreting medical data.

The study recruited 500 healthy adults between the ages of 35 and 79 from both high and low educational backgrounds and randomly assigned them to receive either an 80-page primer titled “Know Your Chances: Understanding Health Statistics” or a generic booklet containing general health advice. Steven Woloshin, Lisa Schwartz, and H. Gilbert Welch of Dartmouth Medical School were interested in seeing if their primer (which they revised and published in book form earlier this year) positively affected patients’ medical decision-making abilities.

Since the researchers could not ethically publish information about real-life medical decisions, they instead measured participants with an 18-item test of medical data interpretation from hypothetical advertisements, news stories, and clinical scenarios. Possible scores ranged from 0 to 100, with 75 considered “passing” and 90 (the average score of physicians who teach evidence-based medicine) considered “outstanding."

On average, the group that received the risk primer scored 6 to 7 points higher on the test than the other group – a gap that is equal to about one-third of the difference between the scores of medical experts and people with other postgraduate degrees. The researchers concluded that a primer on understanding health risks improved participants’ data interpretation skills, and that the effect size was similar across two groups with different educational status.

The bottom line? Doing a little homework before going to see the doctor (by reading this book or another source of information on health risks) could be well worth your time.