Tuesday, September 20, 2011

For cardiovascular prevention, is this Figure worth a thousand words?

A previous AFP Community Blog post discussed challenges involved in recommending aspirin prophylaxis. Although aspirin reduces the risk of cardiovascular events in persons with no history of coronary artery disease, the absolute risk reduction is relatively small, and needs to be balanced against the inconvenience of taking a daily medication and side effects such as gastrointestinal bleeding. Family physicians who engage in shared decision-making with patients about aspirin may find it difficult to put these statistical risks and benefits in perspective.

In their clinical review "Global Risk of Coronary Heart Disease: Assessment and Application," which appeared last year in AFP, Drs. Anthony Viera and Stacy Sheridan included an easily understandable Figure that illustrated the benefits of 10 years of aspirin chemoprevention among 1,000 persons with a 10 percent 10-year global risk of coronary heart disease. However, as pointed out in a Letter to the Editor published in the September 15th issue, that Figure did not include an illustration of the potential harms of aspirin chemoprevention. In response, Drs. Viera and Sheridan have proposed modifying the figure as follows:

The pictograph shows a population of 1,000 men 45 to 59 years of age who have a 10 percent global risk of a coronary heart disease (CHD) event and who have been receiving aspirin for 10 years to reduce their risk. Green faces represent the number of men who would not benefit because they are not among the 10 percent predicted to have a CHD-related event. The red faces represent the approximate number of men who would have an event despite receiving aspirin. The yellow faces represent the men who would not have an event because it was prevented by aspirin. The reddened rectangle highlights the approximate number of people who would have a gastrointestinal bleed. The red X indicates the one person on average who would sustain a hemorrhagic stroke as a result of receiving the aspirin.

Reprinted with permission from Dr. Chris Cates' EBM Web site. http://nntonline.net/visualrx. Accessed May 23, 2011.

Does this figure exemplify the adage that "A picture is worth a thousand words," or does it oversimplify a complex medical decision? What do you think?