It starts simply enough: Drug companies provide clipboards and notepads emblazoned with their logos to medical students.
But even these trivial handouts have a subliminal impact - they influence the brand of drugs favoured by the students, according to a new research paper.
"We know that even trivial gifts operate on an unconscious level and influence us in ways we don't appreciate ourselves," said David Grande, whose study was published yesterday in Archives of Internal Medicine.
This issue is at the heart of one of the biggest ethical dilemmas in medicine - the influence of drug company marketing on the drugs doctors prescribe and on the research they carry out.
Another study also released yesterday found that 29 per cent of published cancer studies reported a conflict of interest - most commonly, industry funding of research. In these cases, company-sponsored trials tended to conclude the drugs help patients.
Dr. Grande, an internal-medicine specialist at the University of Pennsylvania, says it is possible to change the culture of freebies, which can be detrimental to patient care, by acknowledging that "when promotional trinkets litter the practice environment, they influence drug preference and research."
Dr. Grande's clinical trial involved 352 fourth-year medical students at the University of Miami and the University of Pennsylvania.
The control group wasn't given any promotional paraphernalia, but 198 students were unknowingly exposed to small branded products such as clipboards and a notepad from the maker of Lipitor.
The popular medication to lower cholesterol is one of the most heavily promoted drugs of its type in the United States.
The students exposed to the corporate freebies who attended the University of Miami, which has no policy against accepting gifts from pharmaceuticals, preferred Lipitor over Zocor, which is available generically under the name of simvastatin and is less costly.
The University of Pennsylvania students exposed to the Lipitor products also favoured Lipitor, but not to the same degree as their University of Miami counterparts. Dr. Grande suggested that the University of Pennsylvania's policy of prohibiting most gifts, meals and drug-company samples helps students maintain greater independence from drug firms.
Attitudes toward Lipitor and Zocor were measured through a test involving matching the brands to attributes such as pleasant and unpleasant, and through a questionnaire about the drugs' safety, superiority, efficacy and convenience.
The research illustrates the pernicious influence of even the most trivial gifts, Dr. Grande said, but also the importance of medical schools' conflict-of-interest guidelines and teachings about the persuasion tactics of pharmaceutical firms.
Many doctors do not believe they are susceptible to the drug firms' symbols or logos, despite evidence to the contrary.
"I remember as a medical student there was a box next to all the student mail boxes full of drug company trinkets: pens, notepads, stationery, clipboards," Dr. Grande said. "This is the first study to measure the influence of these giveaways in a clinical context."
The second study reviewed 1,534 cancer studies published in 2006 in eight prestigious medical journals, including The New England Journal of Medicine and The Lancet Oncology. Nearly one-third of the papers disclosed a conflict of interest, the most frequent of which was industry funding (17 per cent), followed by a study author who was an industry employee (12 per cent). When a conflict of interest was present in drug trials, the studies were more likely to report a positive outcome, concluded the study in Cancer, the American Cancer Society's peer-reviewed journal.
As well, research funded by industry was more likely to focus on treatment, and less likely to focus on epidemiology, prevention, risk factors, screening or diagnostic methods. Studies supported by industry were also more likely to use study designs that yielded positive results.
"Attempts to disentangle the cancer research effort from industry merit further attention, and journals should embrace both rigorous standards of disclosure and heightened scrutiny when conflicts exist," concluded Reshma Jagsi, lead author, and a physician in radiation oncology with the University of Michigan.
As well as relying on industry funding for their research, doctors may receive consulting fees from, own stock in and hold leadership positions within organizations that profit from selling the drugs and devices under investigation, she said.
Because of the complexity and controversy of industry-funded research, medical journals require authors to disclose potential conflicts of interest. However, that may not be enough.
"The first critical step is to recognize that these conflicts are there," Dr. Jagsi said. "But they don't say whether the study is invalid."
The study shows that, consciously or unconsciously, individuals with a conflict of interest are more likely to be biased in their analyses.
If society wishes to minimize this potential for bias, it needs to support public funding for medical research so scientists aren't forced to turn to pharmaceutical companies, the study concludes.