Effects of additional context information in prescription drug information sheets on comprehension and risk and efficacy perceptions

OBJECTIVE: To determine how additional explanatory text (context) about drug side effects in a patient medication information handout affected comprehension and perceptions of risk and efficacy. METHODS: We conducted an online experiment with a national sample of 1,119 U.S. adults with rheumatoid arthritis and related conditions, sampled through random-digit dialing, address-based sampling, and online ads. We randomized participants to receive one of several versions of a patient information handout for a fictitious drug, either with or without additional context, then measured comprehension and other outcomes. RESULTS: Additional qualitative context about warnings and side effects resulted in lower comprehension of side effect information, but not information about uses of the drug or warnings. The effect of additional context on risk perceptions depended on whether the medication handout was delivered online or through the mail. Those who received a hardcopy of the handout with additional context had higher perceived risk of side effects than those who saw the version without additional context. CONCLUSION: More clarifying information is not always better and may lead to cognitive overload, inhibiting comprehension. PRACTICE IMPLICATIONS: Additional research should further explore effects of context in online vs. hard-copy formats before practice implications can be determined. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40545-021-00386-9.