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

Abstract

Objective: To examine the effect of attending a medical school with an active policy on restricting gifts from representatives of pharmaceutical and device industries on subsequent prescribing behavior.

Design: Difference-in-differences approach.

Setting: 14 US medical schools with an active gift restriction policy in place by 2004.

Participants: Prescribing patterns in 2008 and 2009 of physicians attending one of the schools compared with physicians graduating from the same schools before the implementation of the policy, as well as a set of contemporary matched controls.

Main outcome measure: Probability that a physician would prescribe a newly marketed medication over existing alternatives of three psychotropic classes: lisdexamfetamine among stimulants, paliperidone among antipsychotics, and desvenlafaxine among antidepressants. None of these medications represented radical breakthroughs in their respective classes.

Results: 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.

Conclusion: Exposure to a gift restriction policy during medical school was associated with reduced prescribing of two out of three newly introduced psychotropic medications.