title: Residency training: the King-Devick test and sleep deprivation: study in pre- and post-call neurology residents.
abstract: OBJECTIVE
  The current study investigates the effect of sleep deprivation on the speed and accuracy of eye movements as measured by the King-Devick (K-D) test, a <1-minute test that involves rapid number naming.
  
  
  METHODS
  In this cohort study, neurology residents and staff from the University of Pennsylvania Health System underwent baseline followed by postcall K-D testing (n = 25); those not taking call (n = 10) also completed baseline and follow-up K-D testing. Differences in the times and errors between baseline and follow-up K-D scores were compared between the 2 groups.
  
  
  RESULTS
  Residents taking call had less improvement from baseline K-D times when compared to participants not taking call (p < 0.0001, Wilcoxon rank sum test). For both groups, the change in K-D time from baseline was correlated to amount of sleep obtained (r(s) = -0.50, p = 0.002) and subjective evaluation of level of alertness (r(s) = 0.33, p = 0.05) but had no correlation to time since last caffeine consumption (r(s) = -0.13, p = 0.52). For those residents on their actual call night, the duration of sleep obtained did not correlate with change in K-D scores from baseline (r(s) = 0.13, p = 0.54).
  
  
  CONCLUSIONS
  The K-D test is sensitive to the effects of sleep deprivation on cognitive functioning, including rapid eye movements, concentration, and language function. As with other measures of sleep deprivation, K-D performance demonstrated significant interindividual variability in vulnerability to sleep deprivation. Severe fatigue appears to reduce the degree of improvement typically observed in K-D testing.
authors.affiliation: Departments of Neurology, University of Pennsylvania School of Medicine, Philadelphia, USA.
authors.forename: Emma C
authors.initials: EC
authors.lastname: Davies
authors.forename: Sam
authors.initials: S
authors.lastname: Henderson
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Balcer
authors.forename: Steven L
authors.initials: SL
authors.lastname: Galetta
mesh_terms: D000328:Adult; D003071:Cognition / Q000502:physiology*; D015331:Cohort Studies; D005221:Fatigue / Q000175:diagnosis / Q000503:physiopathology; D005260:Female; D006801:Humans; D007396:Internship and Residency; D008297:Male; D009462:Neurology / Q000193:education*; D009483:Neuropsychological Tests; D011159:Population Surveillance; D057566:Self Report; D012892:Sleep Deprivation / Q000175:diagnosis* / Q000503:physiopathology*; D014940:Work Schedule Tolerance