Study indicates physicians should be cautious in assessing advertisement claims

Journal of Drugs in Dermatology, April, 2003

The pharmaceutical industry incorporates bibliographical references to clinical trials that endorse their products in their advertisements to cater to the growing evidenced-based medicine movement in physician's prescribing behaviors. This study sought to assess whether the references about efficacy, safety, convenience, or cost of antihypertensive and lipid-lowering drugs listed in industry advertisements supported the promotional claims. Two pairs of investigators independently reviewed advertisements for antihypertensive and lipid-lowering drugs published in six Spanish medical journals in 1997 that had at least one bibliographical reference. Two hundred and sixty-four different advertisements for antihypertensive drugs and 23 different advertisements for lipid-lowering drugs were identified. From this grouping, a total of 125 promotional claims with references were selected. Twenty-three (18%) references from monograpbic works and non-published data on file could not be located. Seventy-nine (63%) of the 125 references were from journals with a high impact factor; 84 (82%) of the 102 references retrieved were from randomized clinical trials. The investigators found that in 45 claims (44.1%; 95% CI 34.3-54.3) the promotional statement was not supported by the reference. The authors recommend that physicians be cautious in assessing advertisement claims that a drug has greater efficacy, safety, or convenience, even though these claims are accompanied by bibliographical references to randomized clinical trials published in reputable medical journals and seem to be evidence-based.

Villanueva P, Peiro S, Librero J, Pereiro I. Accuracy of pharmaceutical advertisements in medical journals. Lancet 2003 Jan 4; 361:27-32.