Objective: To determine the quality of claims in advertisements published in Australian medical publications, describe how benefits and harms are presented, and examine the level of underpinning evidence.
Design and setting: Audit of a consecutive three-month sample of advertisements appearing in six popular Australian medical publications.
Main outcome measures: Proportion of advertisements with quantitative information; proportion of claims conveying clinical outcomes; where retrievable, level of underpinning evidence.
Results: Of 1504 claims, 855 could be substantiated quantitatively. Of these, 45% were supported by compelling evidence (randomised controlled trials or better). Of 13 claims explicitly reporting quantitative outcomes, none provided the absolute risk reduction or the number needed to treat.
Conclusions: Our audit invites greater diligence by pharmaceutical companies in substantiating their claims and greater vigilance among clinicians when reading them.