Side Tracks on the Safety Express

Interruptions Lead to Errors and Unfinished… Wait, What Was I Doing?

ISMP Medication Safety Alert 

In This Article

Effects of Distractions and Interruptions

Distractions and interruptions include anything that draws away, disturbs, or diverts attention from the current desired task, forcing attention on a new task at least temporarily. Attending to the new task increases the risk of an error with one or both of the tasks because the stress of the distraction or interruption causes cognitive fatigue, which leads to omissions, mental slips or lapses, and mistakes. An error reported to ISMP a decade ago is still an excellent example of how easy it is to make an error when distracted and interrupted. A nurse who had just measured a dose of liquid chloral hydrate into a cup was interrupted by a pharmacist on her way to the patient's room. The conversation was social, and the nurse—who often had a cup of coffee in her hand—absentmindedly drank the medication, as if taking a sip of coffee! The nurse had to be driven home.

Distractions and interruptions impact the prospective memory, or the ability to remember to do something that must be deferred.[1] When a person forms an intention, their memory establishes a specific cue to remind them to act. If the task is interrupted and the cue is encountered later, a spontaneous process is supposed to bring the intention to mind. However, individuals are less likely to remember the intention if they are outside the context in which the cue was established.[5] For example, an interruption that causes a nurse to leave the patient's room decreases the likelihood that the nurse will remember to come back to finish the interrupted task. A study on multi-tasking with computers found that 40% of the time, individuals wandered off in a new direction after the interruption ended.[6] They forgot what they were doing before the interruption.

If an individual remembers to go back to the initial task, some of the steps may be omitted or repeated, or the entire task may be repeated. For example, a nurse may re-administer a medication, or a pharmacist may dispense a second dose of medication, forgetting that she had already done so. When returning to a task, it takes time for the working memory to get back to where it was before the interruption or distraction.[7] If the task is complicated, individuals who feel pressured may not spend the time it takes for the working memory to catch up, thereby rushing the task and risking errors. In fact, a study on physician distractions found that interrupted tasks were actually completed in less time than if the task had not been interrupted![4] The researchers suggest that the physicians were rushing, which is especially prone to omissions and other types of errors. New staff are particularly vulnerable to distractions and interruptions because interrupting a new task to do a second task affects how the brain processes and stores the information, thereby compromising the ability to recall the new task correctly at a later date.[8]

Studies have shown that distractions and interruptions early in the completion of a task are more error-prone than those that occur near the end of the task or between subtasks.[9] When interruptions occur at natural breakpoints or transitions between parts of a task, instead of during the busiest moments, errors are less likely. These are also the points at which important notifications may be attended to more closely.