High-priority and low-priority drug-drug interactions in different international electronic health record systems: A comparative study

Objectives: To investigate whether alert warnings for high-priority and low-priority drug-drug interactions (DDIs) were present in five international electronic health record (EHR) systems, to compare and contrast the severity level assigned to them, and to establish the proportion of alerts that were overridden. Methods: We conducted a comparative, retrospective, multinational study using a convenience sample of 5 EHRs from the U.S., U.K., Republic of Korea and Belgium. Results: Of the 15 previously defined, high-priority, class-based DDIs, alert warnings were found to exist for 11 in both the Korean and UK systems, 9 in the Belgian system, and all 15 in the two US systems. The specific combinations that were included in these class-based DDIs varied considerably in number, type and level of severity amongst systems. Alerts were only active for 8.4% (52/619) and 52.4% (111/212) of the specific drug-drug combinations contained in the Belgian and UK systems, respectively. Hard stops (not possible to override) existed in the US and UK systems only. The override rates for high-priority alerts requiring provider action ranged from 56.7% to 83.3%. Of the 33 previously defined low-priority DDIs, active alerts existed only in the US systems, for three class-based DDIs. The majority were non-interruptive. Conclusions: Alert warnings existed for most of the high-priority DDIs in the different EHRs but overriding them was easy in most of the systems. In addition to validating the high-and low-priority DDIs, this study reported a lack of standardization in DDI levels across different international knowledge bases.