What’s New in the Patient Safety World

May 2018

Cost of Interrupting a Radiologist



In several columns we’ve described the impact of interruptions on radiologist performance (see our July 1, 2014 Patient Safety Tip of the Week “Interruptions and Radiologists” and our November 2014 What's New in the Patient Safety World column “More Radiologist Interruptions”) and the impact of fatigue on radiologist performance (see our April 2018 What's New in the Patient Safety World column “Radiologists Get Fatigued, Too”).


In our July 1, 2014 Patient Safety Tip of the Week “Interruptions and Radiologists” we discussed a study that looked at how often a radiologist on-call gets interrupted (Yu 2014). During a typical 8PM to 8AM overnight shift there was an average of 72 telephone calls, with a median call duration 57 seconds, and the average time spent on the phone was 108 minutes. The median interval from the start of one telephone call to the start of the next ranged from 3 to 10 minutes, depending on the time of day.


Then in our November 2014 What's New in the Patient Safety World column “More Radiologist Interruptions”) we noted another study that looked at the impact of telephone calls on radiology residents on-call to determine whether there was a relationship between these and discrepancies on reports (Balint 2014). While there was a only a slight difference in total phone calls per shift between those shifts with and without report discrepancies, there was a statistically significant increase in the average number of phone calls in the 1 hour preceding the generation of a discrepant preliminary report (4.23 vs. 3.24 calls). The authors suggest that one additional phone call during the hour preceding the generation of a discrepant preliminary report resulted in a 12% increased likelihood of a resident error.


Now a new study (Trafton 2018) has utilized the eye tracking methodology we described in our April 2018 What's New in the Patient Safety World column “Radiologists Get Fatigued, Too” to assess the impact of interruptions on radiologists in simulated exercises.


Participating radiologists were given a worklist populated with a mixture of volumetric (e.g., chest CT) and 2-D (e.g., chest radiograph) images and told they had 45 minutes to complete their work. Each worklist contained 11 cases, 4 of which were the experimental cases which contained at least one significant finding (the others were largely uncomplicated normal images).


Phone call interruptions took place on two out of four of the experimental cases. The interruption took place 3min into each case. Upon answering the phone, a prerecorded message simulating a clinician asked them to find a patient from a different worklist and provide a quick diagnostic interpretation. Both prerecorded messages asked the radiologist to examine the case of a patient who was not on the initial worklist who was complaining of abdominal pain. This meant that the radiologist had to exit the current worklist, open a second worklist, and find the patient in question. If the radiologist did not hear the name of the patient, the experimenter played the message again. Once the case had been found, the radiologist was asked to verbally indicate the diagnosis as if relaying it to the referring physician. Verbal responses were recorded using the audio input on the eye-tracking glasses. On average, radiologists devoted 2.2 minutes to the telephone interruption before returning to the original case.


The researchers found that the first telephone interruption led to a significant increase in time spent on the case, but there was no effect on diagnostic accuracy. Eye-tracking revealed that interruptions strongly influenced where the radiologists looked: they tended to spend more time looking at dictation screens and less on medical images immediately after interruption. There was also no evidence of a time cost in response to the second interruption. (Note also that in a second simulation, there was no evidence of a time cost where an interpersonal interruption was not relevant to the task and did not involve medical images.)


The authors were surprised there was no effect on diagnostic accuracy after the first interruption. But that was not unexpected for the second interruption since prior research has shown that practice with a task leads to less disruption in response to interruptions.


Their work suggests that the interruption reduced the amount of time spent examining medical images even when an overall time cost was not observed. The authors felt it likely that the dictation screen serves as an external memory aid that helps the radiologist determine where they have and have not previously examined, which is predicted to be an effective strategy in the cognitive psychology literature.


However, the fact that less time is being spent examining medical images after interruption without a concomitant increase in total time spent per case raises concerns. The authors point out that, in aggregate (for instance over the thousands of cases a given clinic examines each year), they expect this would lead to worse performance on interruption cases as a result.


The authors noted that a number of the radiologists noted that both interruptions employed in this study (phone call and interpersonal interruption) were benign relative to the disruptive interruptions they often face, especially if interrupted more than once. They mentioned that interruptions which require leaving the reading room are particularly disruptive, often leading to the radiologist restarting the interrupted case.


While Trafton and colleagues consider their research to be preliminary, they note that further research is needed to determine best ways to minimize the impact of interruptions. But efforts to reduce interruptions are obviously also desirable. One of the strategies recommended in the Balint study to prevent such interruptions is to have other staff handle phone calls. Additional potential strategies include interruption-free zones and having a separate radiologist or radiology resident handle consultations. The previous study by Yu and colleagues noted that posting preliminary reports on the electronic medical record has likely had a beneficial effect on frequency of calls. They, too, have also begun having medical students assist the on-call radiologist by answering the phone and triaging imaging reports. We added that radiology physician assistants can help with things like contrast injections, etc. during high activity periods that might also interrupt radiologists’ reading. Hospitals having the luxury of larger radiology staffs might have a dedicated second radiologist during high volume periods whose sole responsibility is interpreting images. Note that the latter might also be reading images off-site via teleradiology.


We’ve also stressed that much time can be wasted in tracking down the appropriate physician when communicating significant findings. So anything you can do to facilitate identification of the responsible physician would be a positive step.



Prior Patient Safety Tips of the Week dealing with interruptions and distractions:








Yu J-P, Kansagra AP, Morgan J. The Radiologist's Workflow Environment: Evaluation of Disruptors and Potential Implications. JACR 2014; published online April 26, 2014




Balint BJ, Steenburg SD, Lin H, et al. Do Telephone Call Interruptions Have an Impact on Radiology Resident Diagnostic Accuracy? Academic Radiology 2014; published online September 30, 2014




Trafton D, Williams LH, Aldred B, et al. Quantifying the costs of interruption during diagnostic radiology interpretation using mobile eye-tracking glasses, Journal of Medical Imaging 2018; 5(3), 031406 Published online 2 March 2018







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