Monthly Archives: September 2011

10 steps to better risk communication

Every day, patients are faced with difficult medical decisions.  These decisions invariably involve tradeoffs between risks and benefits.  However, these risks and benefits are often not communicated in a way the patient can understand, if they are communicated at all.  In a commentary in the Journal of the National Cancer Institute, Angela Fagerlin and colleagues highlight 10 methods that have been shown to improve understanding of risk and benefit information.  Their commentary uses examples relating to cancer screening, prevention, and treatment, but the principles should apply in other areas.  Below I summarize the key points; the authors state that the first three recommendations are based on strong evidence, while the rest are based on preliminary evidence.

  1. Communicate using “plain language.”  According to the authors, the average American reads at an 8th grade level, but health education materials are often written at a high school or college level, making the information hard for the average person to understand.
  2. Present statistical information using absolute risk rather than using relative risk or number needed to treat formats.  Changes in risk appear larger when presented using relative risk rather than absolute risk.  Absolute risk is easier for most people to understand than number needed to treat.
  3. Use pictographs when possible when presenting information graphical format.  The authors state that pictographs are easier to understand than other types of graphs, such as bar graphs and pie charts.
  4. Present data using frequencies rather than percentages.  “10% of patients get a bad rash” and “10 out of a hundred patients get a bad rash” mean the same thing, but percentages are more abstract and/or harder to understand for some people.
  5. When discussing treatment complications or side effects, differentiate between baseline risks and incremental risks.  Baseline risks are risks the person would face without any treatment; incremental risks are the risks associated with treatment.  For example, an initial pictograph could show baseline risk and a second pictograph could add a new color to represent the additional people who would experience the side effect as a result of the treatment.
  6. Be aware that the order of presenting risks and benefits can alter risk perceptions.  For example, if the benefits are presented first and the risks second, the risks may be perceived to be more worrisome and common.  This issue can’t be avoided altogether, but can be minimized by summarizing all the information at the end.
  7. When there are numerous risks and benefits, use a summary table.  Many treatments have numerous risks and benefits.  It is easier to compare the risks and benefits if they are presented in a summary table.
  8. Recognize that comparative risk information can bias decision making by altering how a person views his or her own risk.  If a person is given information indicating that their risk of developing a disease is higher than average, they may be more likely decide in favor of an intervention.  Decisions should be based on whether the benefits of the intervention outweigh its risks for an individual person, which can only be decided based on absolute risk.
  9. Consider that providing less information may be more effective.  Presenting more information can distract people from focusing on the key pieces of information that are needed for decision making.
  10. Make clear the time interval over which a risk occurs (e.g., 5-year risk, 10-year risk, 20-year risk).

I recommend reading the entire commentary.  If you don’t have access to the PDF, email me and I will send it to you.

Why the new indication for Vytorin and Zetia should not be approved

I have a guest post up at Merrill Goozner’s blog explaining why Merck’s application for a new indication for its drugs Vytorin (simvastatin/ezetimibe) and Zetia (ezetimibe) should not be approved.  The proposed indication is for the reduction of major cardiovascular events in patients with chronic kidney disease and is based on the results of the SHARP trial.  However, because SHARP compared the combination of simvastatin and ezetimibe with placebo — there was no simvastatin arm — we have no way of knowing if ezetimibe contributed anything to the result.  The FDA requires that combination drugs have additive effects over either drug alone.  Merck has not shown that ezetimibe contributed anything to the effect in SHARP, so the new indication should not be approved.

Addendum January 25, 2012:  Merck issued a press release today stating that the FDA did not approve the new indication.  “Because SHARP studied the combination of simvastatin and ezetimibe compared with placebo, it was not designed to assess the independent contributions of each drug to the observed effect; for this reason, the FDA did not approve a new indication for VYTORIN or for ZETIA® (ezetimibe) and the study’s efficacy results have not been incorporated into the label for ZETIA.”  The SHARP results were incorporated into the Vytorin label (see pages 27-28).

Addendum, May 5, 2015:  Unfortunately, the GoozNews blog is no longer up on the web.

Review of CNN special “The Last Heart Attack”

I have a guest  post up on Gary Schwitzer’s blog critiquing Sanjay Gupta’s promotion of calcium scans and overhyping of extreme diets.