Pharmaceutical companies are required by federal law to include both major and minor side effects in their direct-to-consumer advertising of medications. However, including a plethora of side effects may prevent consumers from weighing the major risks, a new study suggests.
The study, published in Nature, looks at how including both major and minor side effects affects consumer behavior. Researchers, Niro Sivanathan, associate professor of organizational behavior at the London Business School, and Hemant Kakkar, a fourth-year PhD student in Organisational Behaviour at the London Business School, conducted the study.
Across six experiments, comprising over 3,000 U.S. participants, researchers found that when drug ads included all side effects, consumers considered the overall severity of the drug side effects to be lower than when exposed to only major side effects.
Further, the study found that when people viewed the overall severity of the drug to be less, consumers not only preferred the drug more, but they were also willing to pay more for the drug.
For one study, researchers asked a group of people to read print ads for Lunesta. One had both major and minor side effects. The other had only major side effects. Participants that read the ad with more side effects rated it safer.
Another study played a radio ad for Cymbalta. One version had all side effects, the other had just major ones. They found the same result.
Overall, the researchers found that including several side effects in advertisements can dilute each piece of information.
Read the full study here.