It included 352 third- and fourth-year students at two medical schools, one that prohibited most gifts, meals and samples from drug companies and another that permitted such marketing practices.

Of those students, 181 were randomly selected to be unknowingly exposed to small branded promotional items for the cholesterol-lowering drug Lipitor, including a clipboard and notepad used when they signed in for study-related appointments. The other 171 students had no such exposure.

A test measured the students' attitudes toward Lipitor and Zocor (a cholesterol-lowering drug that's available generically and is considered as effective as Lipitor). Among fourth-year students, Lipitor was favored by those who were from the medical school that permitted drug company marketing and were exposed to Lipitor promotional items.

But that wasn't the case among fourth-year students who were from the medical school that prohibited drug company marketing.

"Our results provide evidence that subtle branding exposures are important and influential, as the psychology and marketing literature would suggest," concluded Dr. David Grande, of the University of Pennsylvania, and colleagues.

"Our findings are particularly notable, because they are attributable to simple exposure to promotional items independent of other effects attributable to the social relationships associated with gifts. Our study also suggests that institutional policies, by way of their influence on student attitudes toward marketing, could lead to different responses to branded promotional items."

The study is published in the May 11 issue of the Archives of Internal Medicine.

More information

Education initiatives dealing with drug promotions are described by the World Health Organization .