Many radiologists will experience overnight shift (ONS) work during their career, either as a resident or an attending-level physician. So how does working such hours affect a specialist’s ability to do their job?

Lead author Tarek N. Hanna, MD, with the department of radiology and imaging sciences at Emory University Midtown Hospital in Atlanta, and colleagues studied the impact of ONS work on radiologists, publishing their findings in the Journal of the American College of Radiology.

The team compared how 12 radiologists—five faculty members and seven residents—worked and felt after a “normal workday” and after an ONS. At the start of each work session, the specialists completed a Swedish Occupational Fatigue Inventory (SOFI) survey and then viewed 20 bone radiographs. Advanced eye-tracking technology was used, with participants sitting approximately 15 inches from their workstation.

“Prior studies on fatigue in radiology interpretation have examined diagnostic accuracy and the role of changes in vision as the day progresses (i.e., reduced ability to accommodate or focus after a long day of work), none to date have examined whether the way radiologists examine images changes as they become fatigued or whether these changes could in part explain how or why errors are made,” the authors wrote. “Therefore, the purpose of our study was to use eye-tracking technology to assess the effect of ONS on radiologist fatigue, visual search pattern, and diagnostic performance.”

These are four ways working the ONS was found to impact study participants:

1. Less energy and more physical discomfort

Results of the participants’ SOFI survey results showed how feeling fatigued can negatively impact a trained specialist.

“SOFI results demonstrated worsening on all five variables (lack of energy, physical exertion, physical discomfort, lack of motivation and sleepiness) after ONS,” the authors wrote.

2. More false-negative, false-positive decisions

The bone radiographs study participants were asked to view included 15 with fractures present and five with no fracture at all. During the normal workday, the group totaled 56 false negatives and four false positives. During the ONS, the group totaled 72 false negatives and 7 false positives.

The team explained that ways to improve these performance issues associated with ONS work should be further explored.

“We believe that once fatigue-related changes in search and recognition are objectively documented, environmental changes can be introduced to reverse these effects, such as bright lights, required ambulation, or even periodic breaks,” the authors wrote.

3. Longer total viewing time

Overall total viewing time was significantly higher when participants were fatigued than when they were not fatigued. And as Hanna et al. noted, these longer viewing times did not lead to improved accuracy. Could this lead to even more severe issues down the road?

“Despite this 45-percent increase in time per study, the diagnostic accuracy of our subjects decreased,” the authors wrote. “However, in a real-world reading room setting, radiologists may be forced to continue reading at a quicker pace despite fatigue. We theorize that this could further decrease diagnostic accuracy. This is an area for further investigation.”

4. It took participants longer to fixate on the fracture

The eye-tracking technology revealed that it took participants a mean time of 14.9 seconds to first fixate on the fracture target when fatigued, compared to a mean of 11.1 seconds when not fatigued.

The effect was more extreme in residents than faculty members, but it did impact faculty members as well. “In effect, in their fatigued states, faculty members had eye-tracking parameters more characteristic of nonfatigued residents,” the authors added.

If you'd like additional information, Elizabeth A. Krupinski, PhD, one of this study’s co-authors, wrote a column about fatigue in radiology for the Radiology Business Journal in February 2017.