Sharing information electronically with other hospitals is associated with increased sharing of patients.

objectiveOne potential benefit of greater electronic health information exchange is a reduction in the effort required for patients to switch between providers. We therefore assessed whether hospital participation in health information organizations (HIOs) led to increased patient sharing. DATA SOURCES: Secondary data from 2010 to 2016. STUDY

designUsing hospital-pair and year fixed effects regression models, we assessed change in patient sharing volume following HIO participation by hospitals and compared the effect by the level of market competition and by hospital size. DATA EXTRACTION

methodsWe used national data on hospital participation in HIOs from the American Hospital Association Information Technology Supplement and data on the volume of Medicare patients shared between pairs of hospitals from 2010 to 2016. PRINCIPAL

findingsThe volume of patients shared between hospitals increased by 2.6 percent when both hospitals participated in a health information organization (P = .008, 95% CI: 0.7%-4.5%). This increase was greater in competitive markets (3.1 percent increase, P = .03 95% CI: 0.3%-5.9%) and between large hospitals (4.3 percent increase, P = .007 95% CI: 1.2%-7.3%). Participation by only one hospital in a pair had no effect on patient sharing.

conclusionsOur results suggest that an important policy goal motivating the investment in health information exchange has been at least partially achieved. However, our results also support hospital concerns about the competitive implications of engaging in health information exchange. HIO participation appears to facilitate patient movement between hospitals, likely by lowering switching costs and resulting in greater competition.