OBJECTIVE: We evaluated whether presenting prescription drug efficacy information in direct-to-consumer (DTC) advertising helps individuals accurately report a drug's benefits and, if so, which numerical format is most helpful. METHODS: We conducted a randomized, controlled study of individuals diagnosed with high cholesterol (n=2807) who viewed fictitious prescription drug print or television ads containing either no drug efficacy information or efficacy information in one of five numerical formats. We measured drug efficacy recall, drug perceptions and attitudes, behavioral intentions, and drug risk recall. RESULTS: Individuals who viewed absolute frequency and/or percentage information more accurately reported drug efficacy than participants who viewed no efficacy information. Participants who viewed relative frequency information generally reported drug efficacy less accurately than participants who viewed other numerical formats. CONCLUSION: Adding efficacy information to DTC ads-both in print and on television-may potentially increase an individual's knowledge of a drug's efficacy, which may improve patient-provider communication and promote more informed decisions. PRACTICE IMPLICATIONS: Providing quantitative efficacy information in a combination of formats (e.g., absolute frequency and percent) may help patients remember information and make decisions about prescription drugs
