Sleep and Fatigue Offshore...Future sleep and fatigue offshore studies should build on the presented...
Transcript of Sleep and Fatigue Offshore...Future sleep and fatigue offshore studies should build on the presented...
Copyright of Shell International B.V. CONFIDENTIAL
SLEEP AND FATIGUE OFFSHORE
NOGEPA Meeting 20th June 2019
Vanessa Riethmeister, PhD Health, Safety and Environmental Analyst
1
IMPLICATIONS FOR FATIGUE RISK MANAGEMENT
Copyright of Shell International B.V.
DISCLOSURE OF SPEAKER’S INTERESTS
(Potential) Conflict of Interest See below
Potentially relevant company relationships in connection with event None
• Sponsorship or research funding
• Fee or other (financial) payment
• Shareholder
• Other relationship, i.e. …
• Nederlandse Aardolie Maatschappij B.V. / Royal Dutch Shell
• Nederlandse Aardolie Maatschappij B.V. / Royal Dutch Shell
• /
• /
Copyright of Shell International B.V. CONFIDENTIAL
3
4
5
6
2
1
AGENDA
BACKGROUND
STUDY METHODOLOGY
MAIN FINDINGS
IMPLICATIONS
CONCLUSIONS
Q&A
3
FRM – Fatigue Risk Management
FRMP – Fatigue Risk Management Plan
FRMS – Fatigue Risk Management System
Copyright of Shell International B.V. CONFIDENTIAL
FATIGUED
TIRED
DROWSY
SLEEPY
NOT ALERT
4
Copyright of Shell International B.V. CONFIDENTIAL
WHY IS FATIGUE A PROBLEM OFFSHORE?
• The offshore environment is a high risk environment in which consequences can be severe
• Fatigue is one of the major health & safety risk factors offshore ( e.g. due to shift work & consecutive long work days)
5
Deep Water Horizon Disaster, 2010 Piper Alpha Disaster, 1988
* U.S. Chemical Safety and Hazard Investigation Board. Investigation report volume 3 drilling rig explosion and fire at the Macondo well. 2016; Report No.: 2010-10-I-OS.
• Fatigue offshore is not well understood
(e.g. causes, courses & etiology)
Copyright of Shell International B.V. CONFIDENTIAL
SNAPSHOT OF CURRENT FRM PRACTICES OFFSHORE
• Significant variations of FRMPs based on country legislations and operating companies
• Existing work rostering (partially) based on FRMS (e.g. FAID®)
• In general, more attention is paid to night- and swing-shift workers than day-shift workers
• FRM protocol for HSSE-critical positions
• Fatigue awareness training for workers and supervisors
• Inconsistent use of Journey Management Plans
• Voluntary fatigue/fit-for-duty checks (e.g. the prior sleep/wake calculator)
6
There is still a lot to be learned and improved!
Copyright of Shell International B.V. CONFIDENTIAL
OFFSHORE SLEEP AND FATIGUE STUDY
7
To better understand sleep & fatigue parameters during offshore shift rotations, to improve existing FRMPs
Prevalences, time courses and predictors of sleep and fatigue parameters were investigated.
OBJECTIVE
1. Cross-sectional mixed methods baseline study
METHODS
• Interviews (N=19), Focus Groups (N=47) & Questionnaires (N=260)
• N= 5 platforms (Dutch Central North Sea)
* Work Eat and Sleep: Towards a Healthy Ageing at Work Program Offshore. BMC Public Health. 2016; 16:134.
Copyright of Shell International B.V. CONFIDENTIAL
OFFSHORE SLEEP AND FATIGUE STUDY
8
To better understand sleep & fatigue parameters during offshore shift rotations, to improve existing FRMP
Prevalences, time courses and predictors of sleep and fatigue parameters were investigated.
OBJECTIVE
1. Cross-sectional mixed methods baseline study
2. Intensive longitudinal repeated measures study (28-days)
METHODS
• N= 60 offshore day-shift workers (contractors & permanent staff)
• N= 4 platforms (Dutch Central North Sea)
• Bi-daily objective & subjective sleep and fatigue measures (pre-/post-shift, i.e. morning/evening measures)
• Statistical analyses: (Generalized) linear mixed model analyses
1 week 1 week 2 weeks
Copyright of Shell International B.V. CONFIDENTIAL
SUBJECTIVE & OBJECTIVE MEASURES
• Sleepiness/Sleep quality (Karolinska Sleepiness Scale (KSS), Range [1-9])
• Reaction Times/Alertness
• Sleep parameters/Activity during the day
• Circadian Rhythms (Melatonin & Cortisol)
9
Offshore Days: 2, 7, 13
Continuous
Bi-Daily
Bi-Daily Offshore
No Circadian shift detected
No significant changes over time
* Investigating daily fatigue scores during two-week offshore day shifts. Appl Ergon. 2018;71:87-94.
Copyright of Shell International CONFIDENTIAL
PREVALENCES, TIME COURSES & PREDICTORS RESULTS
10
Copyright of Shell International CONFIDENTIAL
PREVALENCES
• Cross-sectional data: • 73% reported prolonged fatigue
• 41% experienced a ‘Dip’, which 60% experienced on day 10/11
PREVALENCES, TIME COURSES & PREDICTORS RESULTS
11
Copyright of Shell International CONFIDENTIAL 12
PREVALENCES
• Cross-sectional data: • 73% reported prolonged fatigue
• 41% experienced a ‘Dip’, which 60% experienced on day 10/11
• 1 in 7 offshore workers reported severe sleepiness (KSS>6)
each offshore day
• The average daily prevalence of severe sleepiness was 10% in
pre-shift and 19% in post-shift measures
• In the second week, 25% of offshore workers reported severe
sleepiness
PREVALENCES, TIME COURSES & PREDICTORS RESULTS
Traffic light graphs. Percentages of employees in low (KSS≤3), medium (KSS=4-6) and severe (KSS>6) sleepiness categories over the course of a fourteen-day offshore shift period. Green columns indicate low, orange medium and red high fatigue risk.
50
40
10
0%
20%
40%
60%
80%
100%
14-day average
0%
20%
40%
60%
80%
100%
1 2 3 4 5 6 7 8 9 10 11 12 13 14
Daily Pre-shift
40
41
19
0%
20%
40%
60%
80%
100%
14-day average
0%
20%
40%
60%
80%
100%
1 2 3 4 5 6 7 8 9 10 11 12 13 14
Daily Post-shift
Copyright of Shell International CONFIDENTIAL 13
PREVALENCES, TIME COURSES & PREDICTORS RESULTS
2,0
2,5
3,0
3,5
4,0
4,5
5,0
5,5
6,0
6,5
1 2 3 4 5 6 7 8 9 10 11 12 13 14
Mea
n KS
S
Days on shift
Morning Evening
9.0
1.0
Fatigue (KSS scores)
OFFHORE PERIOD
• Post-shift fatigue scores are higher & increase at a faster rate compared to pre-shift fatigue scores
• Peak of fatigue on day 10 (37%)
ACCUMULATION OF FATIGUE
0
2
4
6
8
10
12
14
16
1 2 3 4 5 6 7 8 9 10 11 12 13 14
Num
ber
of w
orke
rs w
ith s
ever
e
sleep
ines
s
Offshore days
Daily prevalences of KSS>6 Pre-shift Post-shift
Copyright of Shell International CONFIDENTIAL 14
PREVALENCES, TIME COURSES & PREDICTORS RESULTS
300
350
400
450
500
550
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
Mea
n (m
in)
Study days
Sleep duration TIB TST
0
200
400
600
800
1.000
1.200
1.400
1.600
0
20
40
60
80
100
120
1 2 3 4 5 6 7 8 9 10 11 12 13 14 Mea
n cu
mul
ativ
e sle
ep lo
ss (m
ins)
Mea
n da
ily s
leep
loss
(min
s)
Days on shift
Acute/Chronic sleep loss Daily sleep loss Cumulative sleep loss
ACCUMULATION OF SLEEP DEBT
OFFHORE PERIOD
• Shorter sleep durations offshore
• Average daily acute sleep loss of 92 min
• Average chronic sleep loss of >2.5 consolidated sleep periods
TIB – Time in Bed TST – Total Sleep Time
Copyright of Shell International CONFIDENTIAL 15
2,0
2,5
3,0
3,5
4,0
1 3 5 7 9 111315171921232527
Mea
n
Study days
Level of Rest
2,0
2,5
3,0
3,5
4,0
1 3 5 7 9 111315171921232527
Mea
n
Study days
Sleep Quality
80
82
84
86
88
90
92
1 3 5 7 9 111315171921232527
Mea
n (%
)
Sleep Efficiency %
0
5
10
15
20
25
1 3 5 7 9 111315171921232527
Mea
n (m
in)
Study days
Sleep Latency
PREVALENCES, TIME COURSES & PREDICTORS RESULTS
SUBJ
ECTI
VE
OBJ
ECTI
VE
PRE-OFFHORE PERIOD Preparation period
• SE% scores decreased, sleep latency, and duration
increased
OFFSHORE PERIOD
• Sleep durations, perceived sleep quality and level of rest
after awakening decreased
• Sleep loss and post-shift sleepiness scores accumulated
over the 14-day offshore work periods
• Post-shift sleepiness accumulation was significantly related
to successive days on shift and chronic sleep loss
POST-OFFSHORE PERIOD Recovery period
• Evening sleepiness scores were high and declined rapidly
SUMMARY
Copyright of Shell International CONFIDENTIAL 16
PREVALENCES, TIME COURSES & PREDICTORS RESULTS
End-of-shift effect – high and increasing post-shift fatigue scores in a 14-day offshore work period
Third-quarter-phenomenon – peak in fatigue scores on day 10/11 of a 14-day offshore work period
Spill-over-effect – leave periods affecting work periods and vice versa For example:
• High & rapidly declining fatigue scores and longer sleep durations in post-offshore work periods • Sleep banking strategies in pre-offshore work periods
POTENTIAL FATIGUE RISK PRONE PERIODS
Copyright of Shell International CONFIDENTIAL 17
PREDICTORS (for individual sleepiness) • Suggestive evidence for differential demographic (age, chronotype), lifestyle (smoking, baseline fatigue) and health (BMI, mental &
physical health) predictors for pre- and post-shift sleepiness scores
low baseline sleepiness scores, older age, earlier chronotypes, smoking and poor level of mental & physical health
low baseline sleepiness scores, younger age, good mental and poor physical health
PREVALENCES, TIME COURSES & PREDICTORS RESULTS
Post-shift
Pre-shift
Copyright of Shell International CONFIDENTIAL 18
PREDICTORS (for individual sleepiness) • Suggestive evidence for differential demographic (age, chronotype), lifestyle (smoking, baseline fatigue) and health (BMI, mental &
physical health) predictors for pre- and post-shift sleepiness scores
low baseline sleepiness scores, older age, earlier chronotypes, smoking and poor level of mental & physical health
low baseline sleepiness scores, younger age, good mental and poor physical health
PREVALENCES, TIME COURSES & PREDICTORS RESULTS
Post-shift
Pre-shift
Copyright of Shell International CONFIDENTIAL
STRENGTHS & LIMITATIONS
STRENGTHS • Mixed methods design & Intensive longitudinal repeated measures study design
• Subjective & objective sleep and fatigue measurements
• (Generalized) Linear mixed model analyses
• Large offshore sample: including contractors, from multiple platforms
LIMITATIONS • Limited sample size in absolute terms
• Offshore logistics
• Bi-daily instead of hourly measures
19
Copyright of Shell International CONFIDENTIAL
CONCLUSIONS
• Study findings add new and unique knowledge to the existing sleep and fatigue literature
• FRMPs should focus on the whole offshore cycle, including pre- and post-offshore work periods
• All offshore workers (including day-shift workers and workers in non-HSSE critical positions) should be covered in FRMPs
• Prolonging offshore shifts beyond two-weeks will likely result in elevated fatigue/sleepiness risk
• Study findings provide important input for the advancement and optimization of existing FRMP and FRMS
20
Z Z
Copyright of Shell International CONFIDENTIAL
RECOMMENDATIONS FOR (OFFSHORE) FRMPs
• Consider accumulating fatigue risk with consecutive (offshore) shift days
• Be mindful of potential fatigue risk prone periods (also applies to JMP & Road Safety)
• Develop Test (cost-effectiveness) Implement fatigue prevention strategies, e.g.:
• Pre-/Post-offshore work period fatigue checks
• Pre-HSSE critical tasks fatigue checks
• Real-time fatigue monitoring
• Sleep Hygiene education
• Caffeine intake/Napping strategies/etc.
21
Data Privacy
Fatigued…what now?
Stigma/ Prejudice !
Intrinsically safe appliances
Copyright of Shell International CONFIDENTIAL
Take home message
• Take the risk of fatigue serious as fatigue affects us all!
• Spent sufficient time on fatigue/alertness management
• Evaluate your own work/work environment and try to identify the fatigue risks and potential mitigation strategies
• Create a culture of trust where people can speak up when they are not alert to prevent mistakes and harm.
April 2019 22
Copyright of Shell International B.V.
Thank you for your attention
23
Copyright of Shell International B.V. CONFIDENTIAL
APPENDIX
24
Copyright of Shell International CONFIDENTIAL
FUTURE RESEARCH
Future sleep and fatigue offshore studies should build on the presented findings to further advance bio-mathematical
fatigue prediction models of FRMS to ultimately improve health and safety of offshore workers.
Specific future research examples
• Cost-benefit analyses of the accumulated fatigue risk in extended offshore periods vs the additional commuting
risk in shorter offshore periods
• Effectiveness of fatigue proofing/prevention strategies offshore, including feasibility studies, impact assessments,
cost-efficiency studies and offshore worker satisfaction surveys
• Intensive longitudinal prospective studies of the consequences of accumulated sleep loss and fatigue
25
Copyright of Shell International CONFIDENTIAL
PVT-B ANALYSES
26
200
220
240
260
280
300
1 2 3 4 5 6 7 8 9 1011121314
Mea
n re
actio
n tim
es (m
s)
Offshore days
0
1
2
3
4
5
1 2 3 4 5 6 7 8 9 1011121314
Mea
n nu
mbe
r of
laps
es
Offshore days
0
1
2
3
4
5
1 2 3 4 5 6 7 8 9 1011121314
Mea
n nu
mbe
r of
err
ors
Offshore days
0
1
2
3
4
5
1 2 3 4 5 6 7 8 9 1011121314
Mea
n nu
mbe
r of
false
sta
rts
Offshore days
Figure. Outcomes of the pre- and post-shift objective fatigue metrics, obtained from the psychomotor vigilance task (PVT-B), over the course of the two-week offshore day-shift periods. Means, standard errors and linear prediction lines are plotted for (1) reaction times, (2) number of lapses, (3) number of errors, (4) and number of false starts.
Copyright of Shell International CONFIDENTIAL
CIRCADIAN RHYTHM ANALYSES
Date Month 2016 27 Footer
19:40
19:47
19:54
20:01
20:09
20:16
20:23
20:30
2 7 13
DLM
O ti
mes
(hh:
mm
)
Offshore days
DLMO
-1,00
-0,80
-0,60
-0,40
-0,20
0,00
0,20
0,40
0,60
19:00 20:00 21:00 22:00
Mea
n ln
cor
tisol
con
cent
ratio
n
Time (hh:mm)
Day 2 Day 7 Day 13
Figure. Outcomes of the circadian rhythm marker analyses. Graph (1) depicts mean salivary cortisol levels and standard errors during the three sampling days (offshore day 2, 7 and 13). Graph (2) depicts dim-light melatonin onset (DLMO) times and standard errors across the three sampling days (offshore days 2, 7 and 13).
Copyright of Shell International CONFIDENTIAL
KSS ANALYSES
28
3,0
3,5
4,0
4,5
5,0
5,5
Pre
Post
Pre
Post
Pre
Post
Pre
Post
Pre
Post
Pre
Post
Pre
Post
Pre
Post
Pre
Post
Pre
Post
Pre
Post
Pre
Post
Pre
Post
Pre
Post
1 2 3 4 5 6 7 8 9 10 11 12 13 14
Mea
n KS
S
Days on shift
KSS difference scores
3,0
3,5
4,0
4,5
5,0
5,5
6,0
1 3 5 7 9 111315171921232527M
ean
KSS
Study days
Morning Sleepiness
3,0
3,5
4,0
4,5
5,0
5,5
6,0
1 3 5 7 9 111315171921232527
Mea
n KS
S
Study days
Evening Sleepiness
Copyright of Shell International CONFIDENTIAL
AVERAGE KSS PREVALENCES
29
45,1
40,6
14,3
0%
20%
40%
60%
80%
100%
14-day average
1 2 3 4 5 6 7 8 9 10 11 12 13 14
Severe 11 8,5 8,9 7,7 13 13 14 17 18 22 17 14 18 19
Medium 33 45 43 45 42 43 43 32 43 38 50 40 34 38
Low 56 46 48 47 46 44 42 51 40 41 33 46 48 42
0%
20%
40%
60%
80%
100%
Daily Average
Copyright of Shell International CONFIDENTIAL
PUBLICATIONS
• Riethmeister V, Brouwer S, van der Klink J, Bültmann U. Work, eat and sleep: Towards a healthy ageing at work program offshore. BMC Public
Health. 2016;16:134.
• Riethmeister V, Bültmann U, Gordijn M, Brouwer S, de Boer MR. Investigating daily fatigue scores during two-week offshore day shifts. Appl
Ergon. 2018;71:87-94.
• Riethmeister V, Bültmann U, de Boer MR, Gordijn M, Brouwer S. Examining courses of sleep quality and sleepiness in full 2 weeks on/2 weeks off
offshore day shift rotations. Chronobiol Int. 2018; 35(6):759-72.
• Riethmeister V, Matthews R, Dawson D, de Boer MR, Brouwer S, Bültmann U. Time-of-Day and Days-on-Shift Predict Increased Fatigue Over Two-
Week Offshore Day-Shifts. Applied Ergonomics, accepted for publication.
• Riethmeister, V.; Bültmann, U.; de Boer, M.; Brouwer, S. Predictors of sleepiness in two-week offshore day-shift workers. Submitted.
Date Month 2016 30 Footer