RESUMEN
BACKGROUND: Recent court decisions have thrown into question the Food and Drug Administration's rules limiting manufacturer promotion of prescription drugs for unapproved uses. We assessed how providing pro forma disclosures or more descriptive evidence context about the data supporting an off-label claim affected physicians' beliefs about drug efficacy. METHODS AND RESULTS: In online and mailed surveys, we randomized national samples of board-certified, clinically active cardiologists, internists, and endocrinologists to receive 1 of 3 information scenarios about a hypothetical drug derived verbatim from excerpts on the website for Vascepa, a prescription fish oil for which Food and Drug Administration specially permitted off-label promotion after a manufacturer lawsuit. The scenarios presented information about the approved on-label indication (severe hypertriglyceridemia), off-label claim + pro forma disclaimers (suggestive but not conclusive evidence for use as an add-on to a statin for patients reaching low-density lipoprotein goal but with persistent moderate hypertriglyceridemia), and off-label claim + evidence context (eg, reports on 3 trials failing to demonstrate cardiovascular benefit of other triglyceride-lowering drugs for such patients). Among 686 respondents (48% response rate), 29% reported receiving off-label information about Vascepa (ie, use as an add-on to a statin) from the manufacturer, and 16% had prescribed it off-label for this purpose. Off-label prescribing was 5 times higher among physicians who received such off-label information (38% versus 7%, P<0.001). For the hypothetical drug, the proportion of physicians endorsing the unproven claim that the drug reduced cardiovascular risk was similar among those randomized to the on-label and off-label claim + pro forma disclaimers scenarios (35% versus 37% [95% CI, -6% to 11%]), but substantially lower among those randomized to the off-label claim + evidence context scenario (21% [95% CI, -24% to 7%]). CONCLUSIONS: Physicians who received company information about the unapproved use of Vascepa were more likely to report prescribing it off-label. Supplementing off-label claims with evidence context improved the prescribers' knowledge and reduced enthusiasm for the unproven, off-label indication of reducing cardiovascular risk.