Measurement of resident fatigue using rapid number naming
OBJECTIVE:Sleep deprivation has a negative effect on neurocognitive performance. The King-Devick test (KDT), which tests speed and accuracy of number-reading, requires integrity of saccades, visual processing, and cognition. This study investigated effects of sleep deprivation in on-call residents using KDT. METHODS:A prospective cohort study was conducted among 80 residents. KDT was performed at the beginning and end of an overnight call shift for the residents in the experimental group. A control group was tested at the beginning of 2 consecutive day shifts. Estimates of hours of sleep, Karolinska Sleepiness Scale (KSS)(1â€¯=â€¯extremely alert, 9â€¯=â€¯extremely sleepy), and time and accuracy of KDT were recorded. RESULTS:42 residents were tested before and after overnight call shifts and 38 served as controls. Change in test time differed between the groups, with the experimental group performing 0.54(SDâ€¯=â€¯4.0) seconds slower after their night on call and the control group performing 2.32(SDâ€¯=â€¯3.0) seconds faster on the second day, pâ€¯<â€¯0.001. This difference was larger in surgical compared to medical residents. CONCLUSIONS:Sleep deprivation was inversely correlated with neurocognitive performance as measured by KDT, with more effect on surgical than medical residents. Further research could investigate whether this test could help determine fatigue level and ability to continue working after a long shift.