Influence of direct to consumer pharmaceutical advertising and patients' requests on prescribing decisions: two site cross sectional survey.

Only the United States and New Zealand allow advertising of prescription drugs directed at patients. US spending on such advertising grew rapidly during the 1990s, reaching $2.47bn (£1650m) in 2000. The dramatic increase in investment by the US pharmaceutical industry is evidence of an expected effect on sales. On the rationale that such advertising provides important information to consumers and patients who may benefit from advertised products, pharmaceutical manufacturers have campaigned in the European Union and Canada for the relaxing of current regulatory restrictions. We examined the relation between direct to consumer advertising and patients’ requests for prescriptions and the relation between patients’ requests and prescribing decisions.