Journal advertisements exert less influence on prescribing than 'drug reps'. However, advertisements cost much less. In the U.S.A., advertisements cost $0.40 per contact compared to US $110 per sales call. Consequently, drug companies can use repetitive advertisements to achieve a much greater impact than most people realise. Most of the data on that impact are not published by drug companies for commercial reasons. Despite potential biases, two recent studies from the U.S.A. undertaken by advertising agencies are interesting to consider. In one experimental study, prescribers were exposed to 3 different levels of advertising intensity over 12 months (i.e. 74 advertisement insertions, 131 advertisement insertions and 192 advertisement insertions).1 More frequent repetition heightened product and message awareness and increased prescriptions. Another study focused on 2278 evaluations by primary care physicians of advertisements in the New England Journal of Medicine.2 Familiarity with the advertisements was positively and significantly correlated with confidence in the claims made in the advertisements. The influence of this familiarity on prescribing attitudes varied, depending on whether physicians saw a 'drug rep' or not, and whether they already prescribed the drug or not. In all cases, increased familiarity with the advertisements encouraged positive attitudes towards ongoing prescribing at the same or at a higher frequency.
Many health professionals believe that advertisements have little or no influence because they are given little or no attention. However, conscious 'take-out' of the rational argument presented in advertisements is only a small part of how advertising works. Advertising raises awareness of the brand and associates it with positive attributes including images that use emotional appeals to subconscious desires (e.g. power, confidence, sex).3 Repetition pushes the drug and the positive attributes towards the top of the mental agenda. Consequently, when the indication presents, the drug and the positive associations will be among the first things that come to mind.4 More frequent advertising often increases sales which then rewards more frequent advertising.
Advertising also has an important indirect effect. Many journals rely heavily on advertising for their survival. This makes it much easier, both consciously and subconsciously, for editors to publish articles that will please their benefactors than to support balanced critical analysis of the scientific evidence.
Advertising would be less of a problem if it were more reliable. Prescribers can improve their critical appraisal of misleading arguments. However, such skills may be no help if doctors lack time to read the evidence. Furthermore, such skills do not protect against more subtle influences. Consequently, advertising free zones are the safest places to improve the quality use of medicines.
For more information about the Medical Lobby for Appropriate Marketing (MaLAM), please contact
Dr Peter Mansfield
MaLAM
PO Box 172
Daw Park SA 5041
Fax/phone (08) 374 2245
