Physician Practice Migration and Changes in Practice Style: An Empirical Analysis of Inappropriate Diagnostic Imaging in Primary Care

Abstract Much interest exists in physicians’ ability and willingness to adapt their practice styles, as research demonstrates that many physicians practice in ways that are not aligned with the best available scientific evidence. We exploit migration patterns of primary care physicians in Massachusetts over a span of 8 years by tracking physician migrations to practice sites comprised of new peers who shared actual physical working space. We examined whether a patient's likelihood of receiving an inappropriate referral for diagnostic imaging, specifically a magnetic resonance imaging (MRI), was associated with a change in the work environment of the referring physician. Study results indicate that migrating physicians changed their practice style for imaging relatively soon after migration in conformance with the average practice style of their new peer group regardless of whether or not the practice style was aligned with evidence‐based standards for diagnostic imaging. To place our results in context, a 1 percentage point difference in average inappropriate MRI referral rates between a migrating physician's new and previous work environment was associated with approximately a 14% change in the probability that a patient received an inappropriate MRI referral. The effect diminished with greater variability in inappropriate MRI referral rates within the new peer group. The results show that physician practice style may deviate from evidence‐based standards and vary markedly among physicians within a work environment. At the same time, physician practice style is also malleable in either direction—more or less likely to deviate from evidence‐based standards in conformance with the average practice style of their new peer group. These results imply that healthcare managers can employ various institutional‐level interventions to influence physician behavior in the direction of evidence‐based practice by including strategies directed towards developing strong peer influence in physicians’ work environments.