Riskier than we think? The relationship between risk statement completeness and perceptions of direct to consumer advertised prescription drugs

Direct to consumer (DTC) prescription drug advertising is one of the fastest growing categories of advertising. Expenditures have increased from about $25 million in 1992 to nearly $2 billion in 1999. Given strong evidence of consumer-driven demand for advertised prescription drugs, research was conducted to assess the extent to which DTC prescription drug advertising provides consumers with the information they need to make an informed evaluation of an advertised drug's relative benefits and risks. Two studies explored the relationship between the completeness of the statement describing drug-associated side effects (the "risk statement") and consumers' perceptions of a drug's safety and appeal. The research manipulated risk statement completeness with regard to the incidence levels of side effects mentioned in the statement (which in turn affected the number of side effects mentioned) and the presence or absence of a numeric indicator of side effect incidence. The research strongly suggests a direct relationship between risk statement completeness and consumers' perceptions of drug safety and appeal. Consumers rate the safety and appeal of drugs described with an incomplete risk statement significantly more positively than comparable drugs described with a more complete risk statement. Implications of the research for the regulation and presentation of DTC prescription drug advertising and advertiser communication practices are discussed.