A systematic review says there is a link between information provided to physicians by pharmaceutical companies and higher prescription frequency but what does that mean?   Are companies with new drugs marketing them more or are they better than previous drugs and thus get prescribed more?  

The authors analyze and describe the findings of 58 studies examining the relationship between exposure of physicians to information from pharmaceutical companies and subsequent prescribing behavior.   All but one of the studies suggested that

(a) no association was detected or

(b) exposure to pharmaceutical company information was associated with lower prescribing quality. 

In the 8 studies that examined the relationship between exposure to pharmaceutical company information and prescribing costs, 7 of the studies indicated that exposure to information was associated with a higher cost of prescribing or no association was detected. For example, one study found that physicians with low prescribing costs were more likely to have rarely or never read promotional mail or journal advertisements from pharmaceutical companies than physicians with high prescribing costs.

However, because most of the studies included in the review were observational studies—the physicians in the studies were not randomly selected to receive or not receive drug company information—it is not possible to conclude that exposure to pharmaceutical information actually causes any changes in physician behavior.

The authors state: "We did not find evidence of net improvements in prescribing, but the available literature does not exclude the possibility that prescribing may sometimes be improved." They conclude, "Still, we recommend that practitioners follow the precautionary principle and thus avoid exposure to information from pharmaceutical companies."

Citation: Spurling GK, Mansfield PR, Montgomery BD, Lexchin J, Doust J, et al. (2010) Information from Pharmaceutical Companies and the Quality, Quantity, and Cost of Physicians' Prescribing: A Systematic Review. PLoS Med 7(10): e1000352. doi:10.1371/journal.pmed.1000352