The frequency and impact of task interruptions in the ICU

Up to 98,000 patients die annually in U.S. hospitals due to human error. Despite epidemiological studies demonstrating the severity of this problem it is still unclear what the contributing factors to human error are. However, in aviation one contributor to accidents is task interruptions. The present study examined the frequency and impact of task interruptions in the Intensive Care Unit. Observational data were collected in the ICU by shadowing nurses. During the 34 hours of observation, 1138 nurse activities were observed, of which 29.4% were interrupted. Consequences of an interruption for the primary task can be abandoning its completion or omissions of some of the tasks steps. The conditional probability that an interrupted task was abandoned was p(abandoned | interrupted) = .12, where the omission of steps of the primary task had a conditional probability of p(omission | interrupted) = .015. A total of six cases that created patient hazards were observed where in five of these cases an interruption preceded directly. The results of the present study indicate that interruptions in the ICU are frequent and are likely to have a negative impact on patient safety.