Effect of Shift, Schedule, and Volume on Interpretive Accuracy: A Retrospective Analysis of 2.9 Million Radiologic Examinations

Purpose: To determine whether there is an association between radiologist shift length, schedule, or examination volume and interpretive accuracy. Materials and Methods: This study was institutional review board approved and HIPAA compliant. A retrospective analysis of all major discrepancies from a 2015 quality assurance database of a teleradiology practice was performed. Board-certified radiologists provided initial preliminary interpretations. Discrepancies were identified during a secondary review by a practicing radiologist or through an internal quality assurance process and were vetted through a consensus radiology quality assurance committee. Unique anonymous radiologist identifiers were used to link the discrepancies to radiologists' shifts and schedules. Data were analyzed by using analysis of variance, t test, or chi(2) test. Results: A total of 4294 major discrepancies resulted from 2 922 377 examinations (0.15%). There was a significant difference for shift length (P<.0001) and volume (P<.0001) for shifts with versus those without discrepancies. On average, errors occurred a mean (6 standard deviation) of 8.97 hours +/-2.28 into the shift (median, 10 hours; interquartile range, 2.0 hours). Significantly more errors occurred late in shifts than early (P<.0001), peaking between 10 and 12 hours. The number of major discrepancies in a single shift ranged from one to four, with a significant difference in the number of discrepancies as a function of study volume (volume for all shifts, 67.60 +/- 60.24; volume for shifts with major discrepancies, 118.96 +/- 66.89; P<.001). Despite a trend for more discrepancies after more consecutive days worked, the difference was not significant (P =.0893). Conclusion: Longer shifts and higher diagnostic examination volumes are associated with increased major interpretive discrepancies. These are more likely to occur later in a shift, peaking after the 10th hour of work.