Assessing trends in hospital system structures from 2008 to 2015

Background: The Affordable Care Act introduced a major systematic change aimed to promote coordination across the care continuum. Yet, it remains unknown the extent to which hospital system structures have changed following the Affordable Care Act. The structure of hospital systems has important implications for the cost, quality, and accessibility of health services. Objectives: To assess trends in the structures of hospital systems. Research Design: We aggregated data from the American Hospital Association (AHA) Annual Survey to the system level. Using a panel of hospital systems from 2008 to 2015, we assessed trends in the number of hospital systems, their size, ownership characteristics, geospatial arrangements, and integration with outpatient services. Results: In the period 2008-2015, there was an increasing percentage of hospitals that were system affiliated as well as growth in the number of hospital systems. A greater percentage of hospital systems that were organized as moderately centralized systems transitioned to centralized systems than to decentralized systems (19.8% vs. 4.7%; P<0.001). In terms of geospatial arrangement, a greater percentage of hub-and-spoke systems moved to a regional design than to national systems (20.0% vs. 8.2%; P<0.05). An increasing trend over time toward greater integration with outpatient services was found in a measure of total system level integration with outpatient services. Conclusions: Our findings suggest that hospital systems may be moving toward more regional designs. In addition, the trend of increasing integration offered across hospital systems overall, and as portion of total integration, suggests that systems may be increasing their services along the continuum of care.