The diffusion of a medical innovation: Is success in the stars?

This paper relates the diffusion of the coronary stent to the presence of prominent or "star" physicians within a local peer group. The paper uses panel data on coronary care in Florida covering the period immediately following the 1995 Food and Drug Administration (FDA) approval of the stent, a significant improvement in coronary angioplasty. Adoption timing and utilization varied considerably across doctors between 1995 and 2001. We consider the role of asymmetric social influence among physicians based on professional status. Defining "star" status as having completed residency at a top-ranked hospital, we find that the diffusion of stents by non-stars depends positively on the number of stars practicing contemporaneously at the same hospitals, while we find no social influence in the opposite direction. The findings indicate that lack of local exposure to star physicians may slow adoption, and clustering of stars in a small number of hospitals may entail welfare costs.