Background: Interruptions have been widely studied in the health care domain, yet the nature of work in healthcare is changing with the pervasive use of electronic health records (EHRs). It is unclear how interruptions are changing with the introduction of new technology.Method: This study examines the nature of interruptions experienced by emergency medicine physicians before and after the transition from a home grown EHR to a commercially available system with electronic nursing documentation and computerized physician order entry (CPOE) capabilities. A minute-by-minute paper-based observation template was utilized to record the type of tasks interrupted (patient room, computer, verbal communication or paper charts/labs) as well as who initiated the interruption.Results: There was a significant difference in the type of tasks performed between the preimplementation and post-implementation (go-live) phase. Physicians spent less time on paper-related tasks (p < 0.01) and more time on computer-related tasks (p < 0.01) in the go-live phase. With the shift in task composition, physicians experienced a significantly higher rate of interruptions of computer tasks (p = 0.05), and a significantly lower rate of interruptions to of paper-based tasks (p < 0.01). There were no significant differences in the source of the interruption between the two phases.Discussion: Given the shifts in the types of tasks interrupted after the implementation of a commercially available system with CPOE, it is important to develop new interruption coping strategies. These strategies might include interface design principles to facilitate interruption recovery, less disruptive tactics for the person initiating the interruption, and providing the physicians with training on test systems with realistic data prior to using the new system to care for patients.Conclusion: It was demonstrated that EHRs change the nature of interruptions experienced during the immediate go-live period. Going forward, exploring methods for mitigating harm associated with this change will be critical in preserving patient safety.