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Concern exists about the effect of extended resident work hours;
however, no study has evaluated training-related performance impairments against
an accepted standard of functional impairment.
To compare post-call performance during a heavy call rotation
(every fourth or fifth night) to performance with a blood alcohol concentration
of 0.04 to 0.05 g% (per 100 mL of blood) during a light call rotation, and to
evaluate the association between self-assessed and actual performance.
Design, Setting, and Participants
A prospective 2-session within-subject
study of 34 pediatric residents (18 women and 16 men; mean age, 28.7 years) in
an academic medical center conducted between October 2001 and August 2003, who
were tested under 4 conditions: light call, light call with alcohol, heavy call,
and heavy call with placebo.
Residents attended a test session during the final week of a
light call rotation (non–post-call) and during the final week of a heavy call
rotation (post-call). At each session, they underwent a 60-minute test battery
(light and heavy call conditions), ingested either alcohol (light call with
alcohol condition) or placebo (heavy call with placebo condition), and repeated
the test battery. Performance self-evaluations followed each test.
Main Outcome Measures
Sustained attention, vigilance, and simulated driving
performance measures; and self-report sleepiness, performance, and effort
Participants achieved the target blood alcohol concentration.
Compared with light call, heavy call reaction times were 7% slower (242.5 vs
225.9 milliseconds, P<.001); commission errors were 40% higher (38.2% vs 27.2%,
P<.001); and lane variability (7.0 vs 5.5 ft, P<.001) and speed variability (4.1
vs 2.4 mph, P<.001) on the driving simulator were 27% and 71% greater,
respectively. Speed variability was 29% greater in heavy call with placebo than
light call with alcohol (4.2 vs 3.2 mph, P = .01), and reaction time, lapses,
omission errors, and off-roads were not different. Correlation between
self-assessed and actual performance under heavy call was significant for
commission errors (r = –0.45, P = .01), lane variability (r = –0.76, P<.001),
and speed variability (r = –0.71, P<.001), but not for reaction time.
Post-call performance impairment during a heavy call rotation is
comparable with impairment associated with a 0.04 to 0.05 g% blood alcohol
concentration during a light call rotation, as measured by sustained attention,
vigilance, and simulated driving tasks. Residents’ ability to judge this
impairment may be limited and task-specific.
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