LAUSR

OBJECTIVES To assess whether previously observed differences in interoperable exchange by physician practice size persisted in 2019 and identify the role of 3 factors shaping interoperable exchange among physicians in practices of varying sizes: Federal incentive programs designed to encourage health IT use, value-based care, and selection of electronic health record (EHR) developer. MATERIALS Cross-sectional analysis of a 2019 survey of physicians. We used multivariable Poisson models to estimate the relative risk of interoperable exchange based on the size of the practice accounting for other characteristics and the mediating role of 3 factors. RESULTS Seventeen percent of solo practice physicians integrated outside data relative to 51% of large practice physicians. This difference remained substantial in initial multivariable models including physician characteristics. When included in models, Federal incentive programs partially mediated the relationship between practice size and interoperable exchange status. In final models including EHR developer, developer was strongly associated with both exchange and integration while practice size was no longer an independent predictor. These trends persisted when comparing practices with 4 or fewer physicians to those with 5 or more. DISCUSSION Public and private initiatives that increase the benefits of interoperable exchange may encourage small practices to pursue it. Technical and policy changes that reduce the costs and complexity of supporting exchange could make it easier for small developers to advance their capabilities to support small practices. CONCLUSION Addressing the gap between small and large practices will take a 2-pronged approach that targets both small EHR developers and small practices.