 This systematic review found that the prevalence of conflict of interest, COI, policies at medical schools and teaching hospitals varies greatly across high-income countries. In Europe, only a few medical schools have strong COI policies, whereas in North America, more medical schools have strong policies. There are no studies available on the impact of COI policies on research outputs and educational quality or content. This article was authored by Alice Fabry, Christine Rasmussen-Hohn, as Jordan Robjartsson, and others.