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Behavioural observation as a means of assessing sleepiness related driving impairment in obstructive sleep apnoea Cover

Behavioural observation as a means of assessing sleepiness related driving impairment in obstructive sleep apnoea

Open Access
|Jan 2020

Figures & Tables

Figure 1.

Mean (SEM) steering deviation throughout the 90 minute drive in severe OSA patients following normal sleep and sleep deprivation.
Mean (SEM) steering deviation throughout the 90 minute drive in severe OSA patients following normal sleep and sleep deprivation.

Figure 2.

Mean frequency (SEM) of behaviours observed per 10 min block throughout the 90 minute simulated drive in severe OSA patients under normal and sleep restriction conditions.
Mean frequency (SEM) of behaviours observed per 10 min block throughout the 90 minute simulated drive in severe OSA patients under normal and sleep restriction conditions.

Figure 3.

Mean frequency (SEM) of behaviours observed per 1 minute time block in the 10 minutes prior to the first crash or non-crash event in severe OSA patients under sleep restriction condition.
Mean frequency (SEM) of behaviours observed per 1 minute time block in the 10 minutes prior to the first crash or non-crash event in severe OSA patients under sleep restriction condition.

Figure 4.

Kaplain-Meier curves showing the cessation of non-verbal facial activities in the 10 mins prior to crash events versus control period prior to non-crash events.
Kaplain-Meier curves showing the cessation of non-verbal facial activities in the 10 mins prior to crash events versus control period prior to non-crash events.

Patient characteristics, sleep study results, time In bed (actigraphy)_

VariableN/Mean(SD)
Males/Females (N)14/3
Age (yrs)53.2 (11.6)
Body-Mass Index (BMI)36.8 (8.0)
Apnea Hypopnea Index (AHI: events/hr)64.6 (18.0)
% of sleep time with SaO2<90%9.9 (15.1
Average SaO2 desaturation4.9 (2.3)
Epworth Sleepiness Scale (ESS)10.6 (5.4)
Time in Bed (mins)
Normal Sleep444 (95)
Sleep Restriction213 (0)

Definitions of non-verbal behaviours in OSA patients_

BehaviourDefinition
Self-centred gestures
Touching headHand touches any point on the face, defined from the jaw line upwards, inclusive of scalp, eyes and ears.
Touching neckHand touches any point on the circumference of the neck, from thorax to nape.
Touching armsHand touches opposite arm, from and inclusive of hand to shoulder.
Touching torsoHand touches upper torso - defined from sternum to collarbone and deltoid to deltoid.
Non-verbal facial activities
YawnProgressive, involuntary opening of mouth during deep inhalation. A closed or open hand may move to cover the mouth during a yawn.
Stretch faceExtension of facial muscles without hands present. May include: stretching of facial features along horizontal or vertical axes, exaggerated raising of eyebrows, or tightening and slight recession of ears and scalp.
Licking lipExtension of tongue onto upper or lower lips, which may be held stationary, or moved horizontally in either direction across the chosen lip.
Biting lipInsertion of either upper or lower lip into the mouth until held between upper and lower front teeth. Both lips may be inserted at the same time.
Postural Adjustments
Tilt torsoTilting of torso in any direction, keeping original point of contact on the seat.
Tilt headTilting of head in any direction, keeping original neck position. A tilting behaviour is not to be recorded if it is a function of another behaviour. i.e. tilting head left to scratch the head.
Shift positionRelocation of seating position marked by the brief rising to fall into a new position on the seat. Rising can occur either through the use of one or two hands pushing down against the armrests, or brief and partial propulsion by the legs.
Exercise shouldersMovement of one or both shoulders in a backwards direction, stretching the shoulders and chest. One or both shoulders may also be rotated from the torso in a clockwise or anticlockwise direction, stretching the shoulders and chest.
Stretch armsRemoval of one or both arms from the steering wheels and full extension of one or both elbow joints, resulting in a stretch of the respective arms muscles.
Non-self-centred-gestures
Play with hairHand extends to hair on scalp or face and commences one of the following behaviours: wrapping hair around fingers, repetitively stroking hair mass, tugs hair against follicle roots, or moving fingers through or under hair mass.
Tap fingersRepetitive initiation and cessation of contact of one or more fingers against a surface. If multiple fingers are in use, they may tap in consecutive motion.
Touch environmentOne or more of digits removed from the steering wheel and placed on an inanimate piece of the surrounding environment. i.e. chair, simulator cupboard.
Eye closures
Closed eyes (>1s)Simultaneous closing of both eyelids for a duration lasting for greater than one second.

Incident rate ratio for exhibiting behaviour_

ConditionTime
IRR95%CI 95%CI95%CI
BehaviourIRRlowerUpperZIRRlowerUpperZ
Crash3.441.746.843.54**1.241.091.403.40**
Self-centred1.020.871.210.261.081.051.124.69**
Non-verbal facial1.120.961.311.381.030.991.061.73
Eye closure2.131.752.607.48**1.241.191.2910.82**
Postural1.491.291.725.48**1.111.081.417.42**
Non-self-centred gestures0.530.360.78-3.28**1.111.031.192.90**

Incident rate ratio for exhibiting behaviour preceding crash or non-crash events_

ConditionTime
IRR95%CI 95%CI95%CI
BehaviourIRRlowerUpperZIRRlowerUpperZ
Self-centred0.860.521.42-0.570.980.91.07-0.37
Non-verbal facial1.020.571.810.060.970.881.08-0.5
Eye closure2.131.423.783.37**1.070.991.171.68
Postural0.910.591.41-0.410.970.891.050.04
DOI: https://doi.org/10.21913/JDRSSesw.v1i1.981 | Journal eISSN: 2206-5369 | Journal ISSN: 2205-0612
Language: English
Page range: 10 - 25
Published on: Jan 1, 2020
Published by: University of South Australia
In partnership with: Paradigm Publishing Services
Publication frequency: 1 issue per year

© 2020 A Vakulin, J Dorrian, TR Duggan, CA Litchfield, KJ Cobb, NA Antic, RD McEvoy, SD Baulk, PG Catcheside, published by University of South Australia
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.