Samore MH (VA Salt Lake City TREP)
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 psychological and organizational factors are that contribute to human error in health care. This situation can be contrasted with aviation and other industries where task interruptions have been identified as one major contributor to accidents. The present study examined the frequency of task interruptions in the Intensive Care Unit (ICU) and their impact on the presence of patient hazards.
Trained observers shadowed ICU nurses for a total of 34 hours of observations. The observers used a time motion paradigm categorizing actions of nurses using five different categories with up to 35 subcategories. Observers also categorized the presence and the cause of an interruption, its duration and its consequences. Another aspect of the observations was that the observers qualitatively collected information about the presence of patient hazards.
A total of 1,138 nurse activities were observed during the observation period. Out of these activities, 29.4% of the activities were interrupted. The consequences of an interruption for the primary task can be abandonment or omission 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 were observed that created significant patient hazards; in five of these cases an interruption preceded immediately.
The results of this study indicate that interruptions in the ICU are frequent and likely have a negative impact on patient safety. The results provide the first evidence for a causal relationship between interruptions and patient hazards.
Currently, more observations are being conducted. The findings of this study will allow development of a better understanding of the causal relationship between task interruptions and patient hazards. Also, these findings have a significant impact on improving patient safety by interventions that target interruptions.