Uncovering differences in interoperability across hospital size.

Background: Small hospitals significantly lag behind large hospitals in interoperable health information exchange. This analysis identifies factors that explain differences in interoperability between these hospital types. We place a particular emphasis on such factors as number of functionalities within electronic health record system (EHR), participation in regional and national networks, and adoption of a dominant EHR.

Methods: Using data from the 2017 American Hospital Association (AHA) Annual Survey Information Technology Supplement (n = 2789 hospitals), we applied a Blinder-Oaxaca decomposition technique to explain differences in each domain of interoperability. Interoperability is defined as a hospitals' ability to electronically send, receive, and integrate summary of care records into their EHR and electronically find patient health information from external sources.

Results: The percentage of small and large hospitals engaged in each interoperability domain increased between 2015 and 2017; however, the gap between these hospital types remained mostly the same. Differences in characteristics explained most of the gap in integrating, finding and receiving the data while differences in characteristics and returns to characteristics were significant in explaining the differences in sending the data. The number of EHR functionalities and participation in national and regional networks were among largest contributors to the gap.

Conclusions: The lack of participation in multiple networks and the number of functionalities in EHRs among small hospitals are key factors that explain the difference in interoperability between small and large hospitals. Policies that incentivize these activities or simplify electronic exchange could reduce gaps in interoperability among hospitals of different sizes.