An analysis of nearly three million radiologic exams has confirmed prior research showing that physicians’ concentration tends to fall off toward the tail end of on-duty shifts. And yes, the diminishment in radiologists’ accuracy may be increased when they’re working especially long shifts and/or plowing through long worklists.

The findings were published online Nov. 20 in Radiology.

Tarek Hanna, MD, of Emory University, Christine Lamoureux, MD, of vRad and colleagues reviewed all major discrepancies between preliminary and final reads from a teleradiology practice’s 2015 quality-assurance (QA) database.

The preliminary interpretations were made by board-certified radiologists. The second looks came from practicing radiologists at contracting hospitals.

The discrepancies were identified by either these second readers or through the telerad practice’s internal QA process, then vetted through a consensus radiology QA committee.

Using unique, anonymous radiologist identifiers to link discrepancies to radiologists’ shifts and schedules, the radiologists found a total of 4,294 major discrepancies resulted from 2,922,377 examinations (0.15 percent discrepancy rate).

The team further found:

• Longer shifts were more likely than shorter shifts to be associated with errors: Shifts without vs. with discrepancies had a mean length of 7.98 hours ± 2.63 vs. 8.97 hours ± 2.28.
• Averaged out, discrepancies began picking up at the nine-hour mark and peaked between 10 hours and the end of the shift.
• A significantly higher number of major discrepancies occurred during the latter portions of shifts.
• Shifts with major discrepancies had significantly higher absolute study volume and higher study volume per hour: For shifts in which a major discrepancy occurred, the total volume was 118.96 ± 66.89, and the mean number of studies per hour was 13.06 ± 6.10.
• In shifts with one major discrepancy or more, the number of errors increased as a function of study volume.

The researchers found no significant difference in number of errors as a function of consecutive days worked.

They acknowledge among their study design’s limitations the use of data solely from a teleradiology practice, noting this model’s likely greater load than average of overnight exams and acute studies, along with its generally quieter work environment and relatively lower x-ray and MRI counts.

“[T]he results of this study advance our understanding of how radiologist shift length, diagnostic volume and consecutive days worked influence major discrepancy rates,” Hanna et al. conclude. “In an ongoing effort to minimize radiologic errors, such information may be useful in evidence-based optimization of shifts and schedules.”

The effect of shift length and exam volume on major discrepancy rates, they add, “should be considered when schedules are crafted and error patterns in individual practices are examined.”