Objective Frequent interruptions are assumed to have a negative effect on healthcare clinicians’ working memory that could result in risk for errors and hence threatening patient safety. The aim of this study was to explore interruptions occurring during common activities of clinicians working in emergency departments.

Method Totally 18 clinicians, licensed practical nurses, registered nurses and medical doctors, at two Swedish emergency departments were observed during clinical work for 2 h each. A semistructured interview was conducted directly after the observation to explore their perceptions of interruptions. Data were analysed using non-parametric statistics, and by quantitative and qualitative content analysis.

Results The interruption rate was 5.1 interruptions per hour. Most often the clinicians were exposed to interruptions during activities involving information exchange. Calculated as percentages of categorised performed activities, preparation of medication was the most interrupted activity (28.6%). Face-to-face interaction with a colleague was the most common way to be interrupted (51%). Most common places for interruptions to occur were the nurses’ and doctors’ stations (68%). Medical doctors were the profession interrupted most often and were more often recipients of interruptions induced by others than causing self-interruptions. Most (87%) of the interrupted activities were resumed. Clinicians often did not regard interruptions negatively. Negative perceptions were more likely when the interruptions were considered unnecessary or when they disturbed the work processes.

Conclusions Clinicians were exposed to interruptions most often during information exchange. Relative to its occurrence, preparation of medication was the most common activity to be interrupted, which might increase risk for errors. Interruptions seemed to be perceived as something negative when related to disturbed work processes.