To the Editor Reducing use of low-value care is now a recognized national priority.1 The Original Investigation by Hong et al2 recently published in JAMA Internal Medicine showed that clinician characteristics, including ownership of imaging equipment, ordering low-value imaging on a prior patient, and high rates of low-value imaging in another clinical scenario, are predictive of low-value imaging for back pain and headache. These findings confirm physician-level variation in use of low-value care found in other studies, and contribute to our understanding of the underlying determinants of use. However, important questions remain regarding appropriateness of use as well as behavioral mechanisms associated with low-value care.