SLEEP 2011 Abstract Supplement

A. Basic Science VI. Chronobiology
Support (If Any): FMCSA award DTMC75-07-D-00006 and ONR/
DURIP grant N00014-08-1-0802
0164
EFFECTS OF CONSECUTIVE NIGHT SHIFT WORK ON
POLICE OFFICER PERFORMANCE
Waggoner L 1,2 , Van Dongen H 1 , Belenky G 1 , Vila BJ 1,2
1
Sleep and Performance Research Center, Washington State University,
Spokane, WA, USA, 2 Department of Criminal Justice, Washington
State University, Spokane, WA, USA
Introduction: Motor vehicle crashes are highly prevalent among police
officers. They often work long and irregular, fatiguing shifts, which may
underlie the increased motor vehicle crash rate in this population. To
examine this issue, we compared police officer driving performance at
the end of a period of night shifts with driving performance at the same
time of day following a normal night’s sleep.
Methods: N=13 police patrol officers (27-46y; 1f) participated in two
randomized experimental conditions in the laboratory. One condition
(post-shift) involved performance testing in the morning immediately
after the last work day of five consecutive days of 10.7h night shifts; the
other condition (control) was conducted at the same time in the morning,
but after a normal night of sleep following three consecutive nights off
duty. In each condition, officers performed two 30-minute high-fidelity
driving simulator test drive sessions, a shooting simulation task, and
four 10-minute psychomotor vigilance test (PVT) sessions (sequence:
PVT, shoot, PVT, drive, PVT, drive, PVT). Mixed-effects ANOVAs
were used to examine the effects of condition and test session on PVT
lapses (RT>500ms) and on lane deviation during simulated driving. One
subject’s driving data was excluded due to a collision that prematurely
ended a simulated drive in the post-shift condition.
Results: Performance was significantly poorer in the post-shift condition
for both driving simulator lane deviation (F[1,465]=9.21, P=0.003)
and PVT lapses (F[1,56]=9.13, P=0.004). Post-drive PVT lapses covaried
significantly with lane deviation (F[1,308]=4.40, P=0.037).
Conclusion: The present, laboratory-controlled results indicate that officers
experience impaired vigilance and degraded (simulated) driving
performance in the morning following a week of night shifts compared
to the morning following a normal night of sleep after three nights off
duty. This suggests that the high prevalence of motor vehicle crashes
among police officers could be mitigated through improved fatigue
management.
Support (If Any): CDMRP award W81XWH-05-1-0099
0165
PSYCHOMOTOR VIGILANCE PERFORMANCE AT TOP OF
DESCENT DURING ULTRA-LONG RANGE FLIGHTS AS
COMPARED TO LONG RANGE FLIGHTS
Wu LJ, Zaslona JL, Van Dongen H, Belenky G
Sleep and Performance Research Center, Washington State University
Spokane, Spokane, WA, USA
Introduction: Ultra-long range (ULR) commercial flights are generally
longer (>16h flight time >10% of the time) than long range (LR) flights
(8h-16h flight time). Both ULR and LR flights are flown with augmented
(3 or 4 pilot) crews to allow for in-flight rest. Nevertheless, because
of the longer duty times involved in ULR flights, they could be more
fatiguing than LR flights. We compared performance on a psychomotor
vigilance test (PVT) at top of descent (TOD), a critical end-of-flight
period when all pilots are to be in the cockpit either flying or monitoring,
in ULR versus LR flights.
Methods: As part of a larger study, N=51 Boeing 777 pilots (age
52.3±6.7y; 1f) were studied during adjacent ULR and LR flight pairings.
A 5-minute PVT ported to a PDA was taken within 1 hour prior to TOD
on each leg of each pairing. Mean PVT reaction times were compared
between ULR and LR within pilots, using mixed-effects ANOVA.
Results: There was no significant difference in mean PVT reaction
times at TOD between ULR and LR flights (F[1,140]=2.77, P=0.10).
PVT reaction times were 294ms±20ms (mean±SE) during ULR flights
and 332ms±20ms during LR flights.
Conclusion: PVT performance at TOD was not significantly different
between ULR and LR flights. While further data collection is ongoing,
this preliminary finding suggests that ULR flights are not inherently
more fatiguing than LR flights despite the longer duty times in ULR
operations.
Support (If Any): Continental Airlines
0166
SUBJECTIVE SLEEPINESS AND FATIGUE AT TOP OF
DESCENT DURING ULTRA-LONG RANGE FLIGHTS
RELATIVE TO LONG RANGE FLIGHTS
Belenky G, Wu LJ, Zaslona JL, Van Dongen H
Sleep and Performance Research Center, Washington State University
Spokane, Spokane, WA, USA
Introduction: Ultra-long range (ULR) commercial flights (>16h flight
time >10% of the time) involve longer duty times than long range (LR)
commercial flights (8h-16h flight time). Both flight types are performed
with augmented (3-4 pilot) crews to allow for in-flight rest. We compared
subjective sleepiness and fatigue during ULR and LR flights at top
of descent (TOD), a critical end-of-flight period when all pilots are in the
cockpit either flying or monitoring.
Methods: As part of an ongoing study, N=52 Boeing 777 pilots (age
52.4±6.7y; 1 female) were studied during both ULR and LR flight pairings.
Subjective sleepiness (Karolinska Sleepiness Scale; range 1-9,
“extremely alert” to “extremely sleepy, fighting sleep”) and subjective
fatigue (Samn-Perelli Fatigue Scale; range 1-7, “fully alert, wide awake”
to “completely exhausted, unable to function”) were measured within 1h
prior to TOD on each leg of each pairing. Sleepiness and fatigue scores
were compared within pilots by flight type using mixed-effects ANOVA.
Results: Subjective sleepiness scores were 3.5±0.2 (mean±SE) during
both ULR and LR flights. Subjective fatigue scores were 3.0±0.1 during
ULR flights and 2.9±0.1 during LR flights. There was no significant effect
of flight type on subjective sleepiness (F[1,154]=0.04, P=0.84) or on
subjective fatigue (F[1,154]=0.11, P=0.74) at TOD.
Conclusion: Despite the longer duty time associated with ULR flights,
subjective sleepiness and fatigue were not significantly different at TOD
in ULR flights relative to LR flights. Further data collection is ongoing
to increase the statistical power of the study.
Support (If Any): Continental Airlines
0167
IN-FLIGHT AND LAYOVER SLEEP DURATION IN
COMMERCIAL AIRLINE PILOTS FLYING LONG RANGE
(LR) VS. ULTRA-LONG RANGE (ULR) FLIGHTS
Zaslona JL, Wu LJ, Van Dongen H, Belenky G
Sleep and Performance Research Center, Washington State University
Spokane, Spokane, WA, USA
Introduction: Recent advances in commercial aviation have made it
possible to increase flight duration beyond long range (LR; 8h-16h flight
time) to ultra-long range (ULR; >16h flight time >10% of the time).
A priori, the longer duty hours of ULR could result in greater risk of
fatigue. A key issue is whether or not ULR flights are associated with
reduced amounts of sleep. To investigate this, we compared sleep during
flights and during layovers for LR vs. ULR flights, in the same pilots.
Methods: As part of an ongoing study, the sleep of N=52 Boeing 777
pilots (ages 52.5±6.7y; 1 female), studied over both LR and ULR flight
pairings, was monitored by actigraphy (Phillips Respironics Actiwatch
Spectrum) from three days before their first flight pairing until three days
after their second flight pairing. All flights were augmented (3 or 4 pilot
crews), allowing for in-flight sleep (as only 2 pilots are needed on
SLEEP, Volume 34, Abstract Supplement, 2011
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