Long Days Make Radiologists Less Accurate

The ability of radiologists to detect fractures after a day of viewing images declines significantly compared to their diagnostic accuracy at the start of the day, according to a report published this month in the Journal of the American College of Radiology.

The authors, from the University of Arizona in Tucson and the University of Iowa in Iowa City, measured reads of 40 attending radiologists and radiology residents as they viewed 60 bone exams, half with fractures and half normal.

"Because of increased visual strain...radiologists' ability to focus on images was reduced making them less accurate after a day reading diagnostic images," wrote lead author Elizabeth Krupinski, PhD, and colleagues.  The radiologists had increased symptoms of fatigue and oculomotor strain.

Although the report notes difference in accuracy was about 4%. The reduced accuracy in later reading included about the same increase in false positives as there was a decrease in true-positives. In other words, errors included incorrectly diagnosing fractures that didn't exist and missing those that did.

"Radiologists need to be aware of the effects of fatigue on diagnostic accuracy and take steps to mitigate these effects," the authors wrote.

The researchers hypothesized before the study began that radiologists would compensate for their fatigue by taking more time. "This did not happen. Accommodation accuracy (the process by which the eye changes focus) was reduced, reading time was the same. Viewing time was unchanged late in the day and time to report fractures was no different."