[Drug-promoting advertisements in the Dutch Journal of Medicine and Pharmaceutical Weekly: not always evidence based].
OBJECTIVE
To determine and compare the foundation of claims in drug-promoting advertisements in a Dutch journal for physicians and a Dutch journal for pharmacists.


METHODS
A cross-sectional study.


METHODS
We included all the drug-promoting advertisements referring to a randomized controlled trial (RCT) we could find on Medline from 2 volumes of the Dutch Journal of Medicine (Nederlands Tijdschrift voor Geneeskunde; NTvG) and the (also Dutch) Pharmaceutical Weekly (Pharmaceutisch Weekblad; PW). The validity of the advertisements (n = 54) and the methodological quality of the referenced RCTs (n = 150) were independently scored by 250 medical students using 2 standardised questionnaires. The advertisements' sources were concealed from the students. Per journal, the percentage of drug-promoting advertisements having a valid claim and the percentage of high-quality RCT references were determined. Average scores on quality and validity were compared between the 2 journals.


RESULTS
On a scale of 0-18 points, the mean quality scores of the RCTs differed 0.3 (95% CI: -0.1-0.7) between the NTvG (score: 14.8; SD: 2.2) and the PW (score: 14.5; SD: 2.6). The difference between the validity scores of drug-promoting advertisements in the NTvG (score: 5.8; SD: 3.3) and the PW (score: 5.6; SD: 3.6) was 0.3 (95% CI: -0.3-0.9) on a scale of 0-10 points. For both journals, an average of 15% of drug-promoting advertisements was valid (defined as a validity score of > 8 points); 35% of the RCTs referred to was of good methodological quality (defined as a quality score of > 16 points).


CONCLUSIONS
The substantiation of many claims in drug-promoting advertisements in the NTvG and the PW was mediocre. There was no difference between the 2 journals.
Leids Universitair Medisch Centrum, afd. Klinische Epidemiologie, Leiden, the Netherlands.
Annelies E
AE
van Eeden
Rachel E J
RE
Roach
Nynke
N
Halbesma
Friedo W
FW
Dekker
D000329:Advertising / Q000592:standards*; D003430:Cross-Sectional Studies; D019317:Evidence-Based Medicine; D006801:Humans; D010506:Periodicals as Topic; D004364:Pharmaceutical Preparations / Q000592:standards*; D016032:Randomized Controlled Trials as Topic
D004364:Pharmaceutical Preparations