Medical school gift restriction policies and physician prescribing of newly marketed psychotropic medications: difference-in-differences analysis

In 2002 the American Medical Student Association established a PharmFree Campaign to advocate for evidence based, rather than marketing based, prescribing. As part of these efforts, the association released the first “PharmFree scorecard” in 2007, which graded US medical schools on the presence or absence of a policy regulating interactions between students and faculty and representatives of the pharmaceutical and medical device industries. Since the first PharmFree scorecard was adopted, the number of US medical schools with conflict of interest policies has grown exponentially and most now have policies restricting gifts. The American Medical Student Association’s approach to advocating against conflicts of interest among physicians is distinctive for its focus on medical students and medical education. Several organizations have suggested codes of conduct for ethical behavior to establish standards to regulate physician-industry collaborations, including the American Medical Association, the American Association of Medical Colleges, and the Pharmaceutical Research and Manufacturers Association, but each predominantly focuses on interactions with practicing physicians or academic investigators. Exposure to a gift restriction policy during medical school was associated with reduced prescribing of two out of three newly introduced psychotropic medications. For two of the three medications examined, attending a medical school with an active gift restriction policy was associated with reduced prescribing of the newly marketed drug. Physicians who attended a medical school with an active conflict of interest policy were less likely to prescribe lisdexamfetamine over older stimulants (adjusted odds ratio 0.44, 95% confidence interval 0.22 to 0.88; P=0.02) and paliperidone over older antipsychotics (0.25, 0.07 to 0.85; P=0.03). A significant effect was not observed for desvenlafaxine (1.54, 0.79 to 3.03; P=0.20). Among cohorts of students who had a longer exposure to the policy or were exposed to more stringent policies, prescribing rates were further reduced