New study reduces confidence in medication research
Where can you go to find reliable information about health and medication? Those of us who are "in the know" would say peer-reviewed journals, which publish studies that are reviewed and critiqued, often by several researchers, before appearing in print. Unfortunately, as you've heard on our podcast, sometimes researchers report their findings in ways that are confusing, if not misleading - the summary of a study about a link between a junk food diet and IQ made it look like kids who eat too many potato chips are at risk of flunking out of school!
It turns out that misleading research studies are more common than you might think, according to a recent article by Dr. Michael Hochman and Dr. Danny McCormick in the Journal of General Internal Medicine - a large percentage of drug studies, even those appearing in reputable journals, are designed or described in a way that could confuse readers.
The new study's authors looked for four factors that have been criticized by scientific experts:
- Surrogate outcomes: reporting on intermediate effects of drugs, such as a focus on lowering cholesterol. If a medication reduces blood pressure, it may or may not affect the rates of heart attacks or stroke.
- Composite outcomes: grouping multiple factors together, even if they aren't equally important. For example, saying a medication reduces blood pressure and mortality rates is confusing: did the drug affect mortality rates or only blood pressure?
- Disease-specific mortality: these studies reported death from specific causes only. So they might report that a drug reduces the chance that a patient would die from a heart attack, but death from a stroke or other causes would not be considered.
- Reporting relative outcomes: the summaries of these studies reported percentage changes, which can be misleading. The author's example: "reporting that an intervention reduces mortality by 50% when the intervention reduces death rates from 0.0002% to 0.0001%".
Knowing the effects of a medication on blood pressure does not always tell you what the effect will be on the things that are really important, like heart attacks or strokes... Similarly, patients don't care if a medication prevents deaths from heart disease if it leads to an equivalent increase in deaths from cancer.
The 4 factors described above occurred commonly, generally in 1/4 to 1/3 of the medication studies that the authors reviewed. Studies that were funded by drug companies were more likely than non-commercially funded research to use surrogate endpoints and disease-specific mortality when investigating the effectiveness of their medication. Hochman and McCormick surmised that drug companies who fund investigations into the effectiveness of their products may promote endpoints that are more likely to lead to positive results.
What does all of this mean? Newspaper reports about research findings often don't tell the whole story, in part because the manner in which some studies are designed and reported is confusing. Readers need to take research information with a grain of salt. Even though that might increase their blood pressure!
Note: Posts on Family Anatomy are for education only, and are not intended to replace professional or medical advice. If you need to talk to someone about family or mental health issues, you can get a referral from your family doctor.