291
1 INTRODUCTION
Maritimeisaprofessionthatinvolvesalotofphysical
andmentaleffortandmanyrisks.Officersplayarole
inensuringthesafetyoflifeandinthedevelopment
of the healthy working attitude of the crew. Deck
cadetsarealsomarinestudentstrainedonboardto
be
watchkeepingofficer.
According to the STCW 78 (amended in 2010)
training standards, deck cadets are obliged to
undertake 12 months of sea training. In Turkey, the
three‐partinternshipsystemiswidelyappliedinthe
undergraduate programs that provide the
qualification of oceangoing watchkeeping officer.
Studentsstudyinginrelated
programsperformtheir
first two internships between June‐September at the
endofeachacademicyearandtheirthirdinternship
between February and September during the third
academicyear(TurkishSeafarersRegulation2016).
Investigation of the Changes in Perceived Sleep Quality
and Quantity among Maritime Students in Relation to
Long Term Sea Training
H.Yılmaz,E.Başar&A.Ayar
KaradenizTechnicalUniversity,Trabzon,Turkey
ABSTRACT: Maritime students spend a certain period of their training on board, depending on their
qualifications. Deck officer candidates (deck cadets) must perform an open sea internship on commercial
vesselsforoneyear.Deckofficersareamongtomemberofcrewwithimportantresponsibilitiestocooperate
with the Master during voyage including being involved in navigation and port watches as well as
maintenance of the ship and its safety equipment. Deck cadets perform their practical training between
academiceducationperiodsaccordingtogeneralpracticeinTurkey.Theycanbesubjectedtounusualworking
hours and rest
periods during the mission on the ship. Considering the importance of adequate sleep for
productivity, vigilance, sustaining attention and even over‐all health and well‐being,it is not only sleep
quantity butsleep quality is critical.The aim of this study was to investigateof the effect of the long
‐term
onboardtraining(aprox.7months)onthesleepquantityandqualityofthemaritimestudents.Dataregarding
sleepquantityandperceptivequalityamongthesubjectswereobtainedbyusingPittsburgSleepQualityIndex
(PSQI).PSQIisascaleprovidinginformationontypeandviolenceofsleepdisordersandthe
qualityofsleep
during the past month. A total of 60 maritime students were asked to fill PSQI before and after onboard
training. Demographical information such as age, gender, weight, height and information regarding the
internshipwerealsoobtained.Ofthestudents43.3%ratedaspoorsleeperbeforetheinternshipandthisratio
increasedto73.3%aftertheinternship.Aprominentdecreaseinsleepqualitywasdetermined.Sleepduration
did not change significantly. This study showed a significant negative effect of onboard training on sleep
quality among participants and they did not recover within a month after returning from the sea which
indicatespotentiallongtermconsequencies.
http://www.transnav.eu
the International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 12
Number 2
June 2018
DOI:10.12716/1001.12.02.09
292
Jeźewska et al. (2006) stated that students at sea
are more vulnerable to the stress compared to
experienced officers, due to reasons such as social
relationships in the marine environment, physical
burdens, lack of control and lack of support. The
World Health Organization sees work‐related stress
sourcesas
determinantsofhealthandillness.
It is known that the shift system and working
hoursattheshipalsoaffectthehealthoftheseafarers.
Many studies in the literature show that working
hourscausesleepingproblemsinseafarers(Hystad&
Eid 2016, Jepsen et al. 2015, Yılmaz 2012).
An
individualshouldbeginsleepingsimultaneouslywith
the biological clock for maximum benefit from the
sleep. If sleep time is not synchronized with the
biologicalclock,propersleepbecomesdifficult.
The schedules of watchkeeping in vessels may
conflict with the individualʹs biological clocks
(Hystad&Eid2016,Yılmazet
al.2013,Calhoun1999,
Colquhoun et al.1988). This situation can disrupt
sleepingandsleep qualityat a significantlevel, and
adversely affect both the general health and the
professionalperformanceofthepersonduetolackof
sleep.
Maritime students have to learn a wide range of
tasks and procedures during the limited training
period at the ship. They have to work with
professional seafarers because they do job based
learning. It is well known in the industry that deck
cadets are used as “joker” member in reducing the
workload of the officers and the crew. They are
subjected to unusual working and resting
hours for
thesereasons(Yıldızetal.2016,Magramo&Gellada
2009).
Whenthenewsoftheaccidentonthecommercial
vessels isexamined, it is understood that the cadets
areinthetragedicalsituation.In2017,traineeKshitji
wasfounddeadinthecargoareaofacontainer
ship;
in 2016, one of the two trainees was died while
unlashingtheforwardgantry cranewiththebosunon
abulkcarrier;in2012,JonathanMartin,a14‐year‐old
intern who died on a training ship by falling from
high...Theseeventsareonlyafewofthe
9210results
that you have seen when you search for web sites
relatedtointerndeaths(URL4‐7).
When adaptationproblems, stress, workload and
working time factors are combined, it can be
predictedthatluckytrainees‐whohavenotsuffered
any accidents or survived‐ continue to their
educational life on
board and in the academy as
ʺunhealthyʺ.
Inthisstudy,itwasaimedtoinvestigatetheeffect
of thelong‐term onboard training(aprox. 7 months)
on the sleep quantitiy and quality of the maritime
students. The Pi ttsburg Sleep Quality Index (PSQI)
wasadministeredto60studentsbeforeand
afterthe
onboardtrainingperiod.
2 METHODS
2.1 Participants
Inthisstudy, PSQI was appliedto Turkishstudents
who will take a long term internship, and their
sleepingqualitiesduringschoollifeweredetermined
firstly.Thisquestionnairehasbeenappliedinrelation
to the last month that does not include
the exam
process. Secondly, the PSQI was repeated a month
later the studentsʹ disembarkation. Data collection
was completed in 11 months (December 2015‐
November2016).
2.2 DemographicVariables
Theindividualsinvolvedinthestudyarerequiredto
have a seafarerʹs medical report, have not passed a
diseasewithinthepast
month,havetobetakentoa
long‐terminternshipandhavepersonalrations.
Theparticipantʹsage,height,weight,genderdata
and the duration of internship, ship type, average
dailywork/rest/sleep/nightsleephoursonboard
were obtained with the help of student information
form.
2.3 DataCollectionandItems
The Pittsburgh Sleep Quality Index (PSQI) is a self‐
ratedquestionnairewhichassessessleepqualityand
disturbances over a 1‐month time interval. Nineteen
individualitems generatesevenʺcomponentʺscores:
subjectivesleepquality,sleeplatency,sleepduration,
habitual sleep efficiency, sleep disturbances, use of
sleeping
medication, and daytime dysfunction. Each
component takes a score between 0‐3 (ʺ0ʺ is very
good,ʺ3ʺ is very bad) and the sum of 7 component
scoresistheglobalPSQIscore.Theglobalscorehasa
valuebetween 0‐21. Thehigher theglobal score, the
worse the
sleep quality. A global PSQI score of≤5
indicatesʺgood sleep qualityʺ and a score of >5
indicatesʺpoorsleepqualityʺ.Thepoorsleepquality
suggests that at least two of the above mentioned
components are severely impaired or three of the
components are moderate impaired. The index is
known
to be valid and reliable in Turkish society
(Buysseveark.,1989;Ağargünveark.,1996).
2.4 InformationofParticipants’Internship
Participants in the study were trained in bulk
carriers(15%),dry/generalcargovessels(23.3%),Ro‐
Ro(6.7%),container(11.7%)andtankers(43.3%).The
average duration of internship is 6.9
months (SD
0.73).
Theaveragedailystudyreportedbystudentswas
between10and21hours(mean15.4±2.4);meandaily
rest between 3 and 14 hours (mean 8.2±2.1); mean
daily sleep was between 3 and 10 hours (mean
6.2±1.4) and mean daily nighttime sleep varied
between0and 8 hours (mean
5.2±1.8).ʺDaily sleepʺ
referstoall the sleepprocesses that occur within24
hours, theʺnight sleepʺ expression at midnight and
thesleepprocessesthatoccuraroundit.
293
Figure1.Subjects’globalPSQIscoresbeforeandafterinternship
2.5 AnalysisofData
Participantsʹ global PSQI scores, subscores, gender,
age,typeofship,dailyaveragework/rest/sleep/night
sleep hours, watchkeeping system and duration of
internship were assessed using excel data analysis
tools. Frequency distribution, mean and standard
deviationsaretakenintoaccountintheevaluations.
Asthevaluesofthefour
womenwhoparticipated
inthestudydidnotcauseanysignificantdifferences
intheaveragePSQIscores,theywereevaluatedin60
people without discrimination between men and
womeninthecalculations.
3 RESULTS
Sixty individuals (56 men, 4 women) with proper
suitability(seafarerʹshealthcertificate)participatedin
the
study. The mean age was 23.1 years (21.3‐26.8)
andthemeanbodymassindexwas24.0kg/m2(18.5‐
32.4).
TheaverageglobalPSQIscoreofthestudentswas
5.6±2.9beforetheinternshipand7.6±3.5afterthe
internship.
Before the training, 34 subjects (56.7%) had
a
global PSQI score of≤5 while the remaining 26
subjects(43.3%)hadascore>5.
After the internship, 16 subjects (26.7%) had a
globalscore≤5,and44people(73.3%)hadascore>5.
For each participant, global PSQI scores before and
aftertheinternshipareshownin
Figure1.Whenthe
globalPSQIscoreis≤5,itisevaluatedasʺgoodsleep
qualityʺ and when it is> 5, it is considered asʺpoor
sleepqualityʺ(Buysseetal.1989).
The frequency distributions of the global PSQI
scores before and after the internship are shown in
Figures2and
3.
The mean and standard deviation (SD) values of
the participantsʹ global PSQI scores and component
scores before and after the internship, are given in
Tables1and 2. Meanand SDvaluesofPSQI scores
werecalculatedseparately accordingtogender, age,
typeofship,dailyaveragework/
rest/sleep/night
sleephours,shiftsystemandinternshipperiod.Ifthe
post‐internship scores is more than pre‐training
scores that means sleep quality was affected
negatively.
Figure2. Frequency distrubation of global PSQI scores
beforeinternship
Figure3.FrequencydistrubationofglobalPSQIscoresafter
internship
WhenPSQIsubscoreswere comparedbeforeand
afterthe internship, itwas determinedthatthe total
subscoresforalltheindividualschangedasprovided
inFigure4.
Figure4. Total scores of PSQI subscales before and after
onboardtraining
294
Table1.ScoresofglobalPSQIandsubscalesbeforeinternship(mean,standarddeviation)
__________________________________________________________________________________________________
BeforeInternship
ScoresofPSQIsubscales
__________________________________________________________________________________________________
Global Sleep Sleep Sleep Sleep SleepUseof Daytime
PSQI quality latency duration efficiency disturbance sleeping dysfunction
medication
__________________________________________________________________________________________________
n MeanSD MeanSD MeanSD MeanSD MeanSD MeanSD MeanSD MeanSD
__________________________________________________________________________________________________
Gender
Female4 3.5 1.0 1.0 0.0 0.5 1.0 0.5 0.6 0.0 0.0 0.8 0.50.0 0.00.8 1.0
Male56 5.8 2.9 1.1 0.8 1.4 1.0 1.1 1.0 0.4 0.7 1.1 0.40.0 0.00.7 0.8
All60 5.6 2.9 1.1 0.7 1.3 1.0 1.1 1.0 0.4 0.7
1.0 0.40.0 0.00.7 0.8
Age(Year)
21‐2451 5.6 2.9 1.2 0.8 1.3 1.0 1.1 1.0 0.4 0.7 1.0 0.40.0 0.00.7 0.9
24‐279 5.4 2.9 1.0 0.7 1.2 1.1 1.1 1.2 0.2 0.4 1.2 0.40.0 0.00.7 0.7
TypeofVessels
Bulkcarrier
9 4.8 2.5 0.7 0.7 1.3 1.1 1.3 1.0 0.0 0.0 1.0 0.50.0 0.00.4 0.5
Dry/GeneralCargo 14 6.4 3.8 1.4 0.8 1.7 1.1 1.0 1.1 0.6 0.9 1.1 0.30.0 0.00.6 0.9
Container7 5.3 2.0 1.3 0.8 1.1 0.9 1.0 1.0 0.1 0.4 1.0 0.6
0.0 0.00.7 0.8
Ro‐Ro4 6.5 2.4 1.5 1.0 1.8 0.5 0.8 1.0 0.8 0.5 1.0 0.80.0 0.00.8 1.0
Tanker26 5.4 2.8 1.1 0.6 1.0 1.0 1.2 1.0 0.3 0.6 1.0 0.30.0 0.00.8 0.9
(Chemical/Cruide)
DailyWorkingHours
10‐129 4.6 1.7 0.9
0.6 1.2 0.8 0.7 0.9 0.2 0.4 0.8 0.40.0 0.00.8 1.0
13‐1513 6.0 2.8 1.1 0.6 1.6 1.0 1.2 1.1 0.4 0.8 1.1 0.50.0 0.00.6 0.8
16‐1835 5.8 3.2 1.2 0.8 1.2 1.0 1.2 1.0 0.4 0.7 1.1 0.40.0 0.00.7
0.9
19‐213 4.3 2.5 1.0 0.0 1.0 1.0 1.0 1.0 0.3 0.6 1.0 0.00.0 0.00.0 0.0
DailyRestingHours
3‐54 5.3 2.8 1.0 0.0 1.0 0.8 1.3 1.0 0.5 0.6 1.0 0.00.0 0.00.5 1.0
6‐839 5.9 3.1 1.3 0.8 1.3 1.0
1.1 1.0 0.4 0.7 1.1 0.40.0 0.00.7 0.8
9‐1111 5.3 2.7 1.0 0.6 1.5 1.1 1.2 1.1 0.3 0.6 1.0 0.60.0 0.00.3 0.5
12‐146 4.5 1.4 0.7 0.5 1.2 0.8 0.8 1.0 0.2 0.4 0.8 0.40.0 0.00.8 1.0
DailySleeping
Hours
3‐47 5.6 3.2 1.1 0.7 1.3 1.0 1.3 1.1 0.3 0.5 1.1 0.40.0 0.00.4 0.8
5‐631 6.1 3.2 1.2 0.8 1.2 1.1 1.2 1.1 0.5 0.8 1.1 0.40.0 0.00.8 0.9
7‐820 5.1 2.3 1.0 0.8 1.5 0.9 0.9 0.8 0.3
0.4 1.0 0.40.0 0.00.6 0.8
9‐102 4.0 2.8 1.0 0.0 1.0 1.4 1.5 0.7 0.0 0.0 0.5 0.70.0 0.00.0 0.0
DailyNightSleepingHours
0‐24 7.5 3.5 1.5 0.6 1.3 1.5 1.0 0.0 1.5 1.0 0.0 0.00.0 0.00.0 0.0
3‐
524 5.8 3.2 1.3 0.7 1.3 1.1 1.2 1.0 0.3 0.7 1.0 0.50.0 0.00.7 0.9
6‐832 5.3 2.6 1.0 0.8 1.3 0.9 1.0 1.0 0.3 0.6 1.1 0.40.0 0.00.6 0.8
ScheduleofWathckeeping(Time)
00‐04/12‐1614 6.1 3.1 1.4 0.6 1.3 1.0
1.1 1.0 0.5 0.7 1.0 0.40.0 0.00.8 0.9
00‐06/12‐181 5.0‐1.0‐1.0‐0.0‐0.0‐1.0‐0.0‐2.0‐
04‐08/16‐2032 5.6 3.2 1.1 0.8 1.3 1.0 1.2 1.1 0.4 0.8 1.1 0.50.0 0.00.7 0.9
08‐12/20‐248 4.9 1.9 1.0 0.5
1.4 0.9 1.1 0.6 0.3 0.5 0.9 0.40.0 0.00.3 0.5
MIXED5 5.4 2.1 1.2 1.1 1.6 1.5 0.6 0.9 0.2 0.4 1.0 0.00.0 0.00.8 0.8
DurationofInternship(Month)
5.1‐6.012 5.6 3.5 1.1 0.8 1.3 1.1 1.3 1.0 0.4 0.7 1.0 0.40.0 0.0
0.5 0.8
6.1‐7.021 5.5 2.3 1.0 0.8 1.3 0.8 0.9 1.1 0.2 0.5 1.2 0.50.0 0.00.8 0.8
7.1‐8.025 5.8 3.2 1.2 0.7 1.3 1.1 1.2 0.9 0.5 0.8 0.9 0.30.0 0.00.6 0.9
8.1‐9.02 4.5 2.1 1.0 0.0 1.0 1.4 1.0
0.0 0.0 0.0 1.0 0.00.0 0.00.5 0.7
__________________________________________________________________________________________________
295
Table2.ScoresofglobalPSQIandsubscalesafterinternship(mean,standarddeviation)
__________________________________________________________________________________________________
BeforeInternship
ScoresofPSQIsubscales
__________________________________________________________________________________________________
Global Sleep Sleep Sleep Sleep SleepUseof Daytime
PSQI quality latency duration efficiency disturbance sleeping dysfunction
medication
__________________________________________________________________________________________________
n MeanSD MeanSD MeanSD MeanSD MeanSD MeanSD MeanSD MeanSD
__________________________________________________________________________________________________
Gender
Female4 7.3 5.5 1.3 1.3 1.5 1.3 1.3 1.3 0.3 0.5 1.3 0.50.0 0.01.8 1.5
Male56 7.6 3.4 1.5 0.8 1.7 1.0 1.2 1.0 0.3 0.6 1.3 0.60.0 0.21.5 1.0
All60 7.6 3.5 1.5 0.8 1.7 1.0 1.2 1.0 0.3 0.6 1.3 0.6
0.0 0.21.5 1.0
Age(Year)
21‐2451 7.6 3.4 1.5 0.8 1.8 1.1 1.2 1.0 0.3 0.6 1.3 0.50.0 0.01.5 1.0
24‐279 7.2 4.3 1.6 0.9 1.3 0.9 1.0 1.0 0.3 0.7 1.4 0.70.2 0.41.3 1.0
TypeofVessels
Bulkcarrier9
7.8 3.5 1.7 0.7 2.0 1.0 1.1 0.6 0.4 0.7 1.3 0.70.0 0.01.2 0.8
Dry/GeneralCargo 14 7.6 4.3 1.4 0.8 1.5 1.2 1.4 1.3 0.5 0.8 1.3 0.60.0 0.01.5 1.2
Container7 7.4 3.8 1.3 1.0 1.6 0.8 1.1 1.2 0.0 0.0 1.4 0.80.0 0.0
2.0 1.3
Ro‐Ro4 7.5 4.5 1.5 1.3 2.5 1.0 0.5 0.6 0.3 0.5 1.3 0.50.0 0.01.5 1.3
Tanker26 7.5 3.1 1.6 0.8 1.7 1.0 1.2 1.0 0.2 0.5 1.3 0.50.1 0.31.5 0.8
(Chemical/Cruide)
DailyWorkingHours
10‐129 6.1 2.2 1.0 0.9
1.7 1.0 0.6 0.7 0.0 0.0 1.0 0.00.0 0.01.9 1.2
13‐1513 7.8 3.8 1.5 0.8 1.8 0.9 1.5 1.1 0.2 0.6 1.5 0.70.0 0.01.4 1.0
16‐1835 7.6 3.6 1.7 0.8 1.6 1.1 1.2 1.0 0.3 0.6 1.3 0.60.0 0.21.5 1.0
19
‐213 10.0 3.6 1.7 0.6 2.7 0.6 1.3 1.5 0.7 1.2 1.7 0.60.3 0.61.7 0.6
DailyRestingHours
3‐54 9.5 3.1 1.8 0.5 2.8 0.5 1.3 1.3 0.5 1.0 1.5 0.60.3 0.51.5 0.6
6‐839 7.8 3.6 1.7 0.8 1.7 1.1 1.2
1.1 0.3 0.6 1.3 0.60.0 0.21.6 1.0
9‐1111 7.1 3.4 1.3 0.8 1.5 0.9 1.3 1.1 0.2 0.6 1.5 0.70.0 0.01.4 1.1
12‐146 5.7 2.4 0.8 0.8 1.5 1.0 0.8 0.8 0.0 0.0 1.0 0.00.0 0.01.5 1.2
DailySleepingHours
3
‐47 10.7 2.1 2.3 0.5 2.1 0.9 1.9 0.9 0.6 0.8 1.7 0.50.3 0.51.9 0.7
5‐631 7.6 3.9 1.6 0.8 1.7 1.1 1.3 1.1 0.4 0.7 1.3 0.60.0 0.01.4 1.1
7‐820 6.6 2.6 1.3 0.8 1.6 1.0 0.9 0.9 0.1 0.2
1.3 0.50.0 0.01.5 0.9
9‐102 5.0 0.0 0.5 0.7 1.0 0.0 0.5 0.7 0.0 0.0 1.0 0.00.0 0.02.0 1.4
DailyNightSleepingHours
0‐24 10.8 3.1 2.3 1.0 2.0 1.2 2.0 1.4 0.8 1.0 1.8 0.50.0 0.02.0 1.4
3‐524
8.7 3.8 1.8 1.1 2.0 1.1 1.3 1.1 0.5 0.7 1.4 0.60.1 0.31.6 1.0
6‐832 6.3 2.8 1.2 0.7 1.5 1.0 0.9 0.8 0.1 0.3 1.2 0.50.0 0.01.4 1.0
ScheduleofWathckeeping(Time)
00‐04/12‐1614 7.2 3.1 1.4 0.9 1.4 1.0 0.9
1.1 0.2 0.6 1.4 0.50.1 0.31.8 1.1
00‐06/12‐181 9.0‐2.0‐1.0‐2.0‐0.0‐1.0‐0.0‐3.0‐
04‐08/16‐2032 7.8 3.7 1.5 0.8 1.9 1.0 1.3 1.0 0.3 0.6 1.3 0.70.0 0.21.4 0.9
08‐12/20‐248 6.9 2.5 1.4 0.5 1.8 1.0
1.4 0.7 0.3 0.5 1.1 0.40.0 0.01.0 0.8
MIXED5 7.8 5.2 1.8 0.8 1.6 1.3 0.8 1.3 0.4 0.5 1.4 0.50.0 0.01.8 1.3
DurationofInternship(Months)
5.1‐6.012 6.2 3.1 1.4 0.8 1.3 0.9 1.0 1.0 0.1 0.3 1.1 0.50.1 0.31.2
0.9
6.1‐7.021 7.9 3.4 1.7 0.9 1.7 1.2 1.1 0.9 0.2 0.5 1.4 0.60.0 0.01.8 0.9
7.1‐8.025 7.8 3.8 1.4 0.8 2.0 1.0 1.2 1.1 0.4 0.7 1.3 0.60.0 0.21.4 1.1
8.1‐9.02 8.5 3.5 1.5 0.7 1.5 0.7 2.0 0.0 0.5
0.7 1.5 0.70.0 0.01.5 0.7
__________________________________________________________________________________________________
4 DISCUSSIONSANDFINDINGS
ThestudentsstudyingattheMaritimeTransportation
and Management Engineering Undergraduate
Programareparticipatedinthisstudy.Thethird‐year
studentsʹsleepqualitywasexaminedbeforeandafter
internship by considering onboard working
conditions.
Aysanetal.(2014)foundthatthemeanPSQIscore
ofthestudents
was6.15±1.9 andratioofpoorsleep
quality (PSQI> 5, bad sleepers) was 59%, in a study
they conducted with Turkish university students
studyinginthefield ofhealth sciences.Saygılıetal.
(2011) found a general PSQI average of 6.9 ± 2.4 in
their study with
Turkish university students at
different levels of education and in different
disciplines (from health to social sciences). 30.5% of
thesestudentswerefoundtobebadsleeper.Baertet
al. (2014) found that 30.4% of first‐year college
students were bad sleepers before the first exam
period in Economics and
Commercial Sciences in
Belgium.
Andruskiene et al. (2016) found that 45.0% of
students were bad sleepers in the study they
conducted with university students in various
maritime departments in Lithuania. In the same
study,itwasseenthatmarinestudentsandalsothird
/ fourth year students had worse sleep quality
than
theothers.Inthisstudy,itwasseenthatthemarine
studentswereʺbadsleepers ʺatahigherrate(43.3%)
than the other departments before the internship.
However, the overall PSQI average of 5.6 ± 2.9
indicatesthatthemaritimestudentshadlowersleep
complaints before the internship for
the Turkish
population.
296
Aftertheinternship, there wasa 2‐pointincrease
(deterioration)inoverallsleepquality(interval0‐21).
While the average sleep quality was close to the
ʺgoodʺ limit with a score of 5.6 ± 2.9 before the
internship,theaveragesleepqualitywasaccumulated
in theʺpoorʺ area with
a score of 7.6 ± 3.5 after the
internship. 43.3% of the pre‐training students were
ʺbadsleepersʺ,butthisratioincreasedto73.3%after
theinternship.
Itwas observedthat thestudentswere subjectto
shift work procedures during onboard training but
continuedtoworkoutsideshifts.As
discussedinthe
STCW78(amendedin 2010)and MLC2006; normal
workinghoursshouldnotexceed8hoursperdayin
portandseaintermsofremuneration;fromthepoint
ofviewoffatigue,themaximumworkinghours shall
not exceed 14 hours in a period of 24 hours
and 72
hours in a period of 7 days. The students reported
thatthe averagedailywork‐up wasbetween 10and
21 hours (mean 15.4±2.4); the average daily rest
between 3 and 14 hours (mean 8.2±2.1); the average
daily sleep was between 3 and 10 hours (mean
6.2±1.4) and
the average daily nighttime sleep was
between 0 and 8 hours (mean 5.2±1.8) in the
internship. In general, they have performed against
the regulations of STCW 78 (amended in 2010) and
MaritimeLaborConvention2006(MLC2006).
Karakoç (2009) reported a mean PSQI score of
6.96±3.19inthestudyofhealth
workersʹsleepquality.
The percentage of those with a PSQI score of 5 or
higher was 76.5%. Çalı yurt (1998) reported average
PSQIscores forshifthealthworkers, nurses,doctors
andjetlagwereas8.26±3.60,6.60±2.69,6.33±2.69and
7.00±2.63 respectively. The mean PSQI score of the
control group without
any work and shift
irregularities was 3.3±1.49. The mean PSQI score of
7.6±3.5determinedbythisstudyshowsthatthesleep
qualityofthestudentsreturningtolandafteronboard
trainingwasasbadasthehealthpersonnelandjet‐lag
longflightstaff.
Table1and2showthedifferences
inPSQIscores
before and after the internship. According to the
tables; there is no significant difference in PSQI
changesbetweenindividualsaged21‐24yearsand24‐
27years.
When ship types are examined, the greatest
increase(deterioration)intheaveragePSQIscorewas
seeninthosewhopracticed
onbulkcarriers.Thisis
followed by cadets on tankers and containers,
dry/generalcargoandRo‐Rovessels.However,when
the n and standard deviations are taken into
consideration, it can be concluded that the worst
deterioration in sleep quality occurs in individuals
performing internships in tankers (n:26, the amount
of
theglobalchangewasmean2.1±0.3).
When the daily average working hours are
examined,itis seenthatthe PSQIscore increasesas
working hours increase. The highest increase in the
PSQI score was seen in 19‐21 hours of employees.
Thisisfollowedby16‐18hours,13‐15
hoursand10‐12
hours respectively. As the average daily rest time
decreased,thePSQIscoreincreased.Thehighestscore
increase was seen in those who rested 3‐5 hours a
day.Thisisfollowedbythosewhorest6‐8hours,9‐11
hoursand12‐14hours,respectively.
The
PSQI score increased as the daily total sleep
duration decreased. The highest score increase
occurredduring3‐4 hoursof sleep. This isfollowed
by 5‐6hours,7‐8 hours and 9‐10 hoursrespectively.
Similarly, when nightly sleep decreased, the PSQI
score increased. The highest score increase occurred
inthe0‐2hoursnightsleepers.Thisisfollowedby3‐5
hoursand6‐8hoursnightsleepers.
Participants reported that they were subject to
variable shift systems throughout their onboard
training duties. In order to be able to make the
classification,the shifthoursthat havebeen covered
in the last month of the internship are taken into
consideration. Accordingly, the individuals were
subjecttothe00‐04/12‐16,00‐06/12‐18,04‐08/16‐20,08‐
12/20‐24 and MIXED shift systems. The MIXED
statementindicatesthatindividualsinthatgroupdo
nothaveashiftscheduleduring
theirworkinghours.
The increase in PSQI peaked on a person subject to
the 00‐06 / 12‐18 shift system. If this data for one
personisignored,themaximumincreaseinscorehas
occurredintheMIXEDgroup,whichdoesnothavea
certainworkingorder.Thisisfollowed
by04‐08/16‐
20, 08‐12 / 20‐24 and 00‐04 / 12‐16 shift systems,
respectively.
WhentheeffectoftheinternshipperiodonPSQI
score increasewas investigated, it wasseen that the
increaseinthescorewasmostprominentamongthe
studentswhoworked
for8‐9months.Thisisfollowed
by 6‐7 months, 7‐8 months and 5‐6 month interns,
respectively. As the training period increased, the
PSQIscoreincreased.
Figures4showsthechanges insleepqualityindex
components for all participants. The greatest
impairment occurred in the field of daytime
dysfunction (C7). This is followed by sleep latency,
subjective sleep quality and sleep disturbance
components, respectively. Individuals experiencing
daytime dysfunction are forced to remain awake
during driving,eating, or othersocial activities, and
can not have enough desire to do anything. It is an
undeniablefactthattheeducational life
andsociallife
of the students in this situation will be adversely
affected. In the habitual sleep efficiency (C4) of the
PSQI components, the total score fell unlike other
components.Sleepefficiencyisroughlycalculatedas
theratioofsleeptimetolyingtime.Thescoreincrease
in the sleep duration
component (C3) suggests that
individualsdonothaveanincreaseinsleeptimes.In
thiscase,itcanbementionedthatthereisadecrease
inlyingtimeaftertheinternship.Itisunderstoodthat
there are individuals who are experiencing sleep
latencyinthesamplepopulation(C2),aswell
asthose
whotendtofallasleepassoonastheyreachthebed.
However, when the total score changes of the
componentsareexamined,itisseenthatthereareno
significant changes in the duration and efficiency of
sleep.
The information in the literature attracts to
attentionthatan
individualwithanormalnighttime
sleep of 8 hours will experience a sleep deprivation
with a 5‐hour nighttime sleep. The only way to
compensate for lack of sleep is to sleep more. For 1
hour of daily sleep loss, sleep deprivation can be
corrected by sleeping one or two
hours more each
night. It is generally said that for short‐term
297
deprivations it can take up to 7 days, and for long ‐
term deprivations it may take several weeks. Sleep
deprivationisknowntoaffecthealthnegatively.For
example, it increases the amount of cortisol in the
blood. Long‐term increases in cortisone can also
trigger disorders such as depression, obesity,
and
heartproblems(Epstein&Mardon2006,URL‐1,URL‐
2, URL‐3). The components of sleep duration in
Figure 4 showed that the students did not tend to
sleep too much to compensate for sleep deprivation
aftertheyhad passedfrom sealife tolandlife. This
may be thought to
be related to the component of
sleepdisturbances (C5). Inaddition, the necessity of
continuing daily life and educational activities may
alsoberelatedtothissituation.
Figures 4 shows a significant increase
(deterioration) in the sleep latency (C2) component.
Individualshavemorethan15minutestofallasleep
suggesting that
have sleep latency. In addition, the
frequency of do not fall asleep in 30 minutes
determinestheseverityofsleeplatency.
Sleep disturbance component (C5) indicates that
individuals experience problems include waking in
themidnightorearlymorninghours,getupfeelinga
need for bath/toilet, cannot breathing comfortably,
coughing
or loud snoring, feeling too hot or cold,
have bad dreams and feeling pain. A significant
increase was determined in the number of people
experiencing toilet/bathroom needs, nightmares and
waking in nighttime or early morning respectively,
after the internship. And that the most severe
complaintisrelatedtowakingupat
midnightorearly
inthemorning.
The researchers of this study conducted another
studyontheenergyconsuptionandsleepstatesofthe
deck officers on the container vessels (Yılmaz et al.,
2018). In that study, the average of bedtimes of the
officerswas7.2hours/day(SD±2.0);
averageofsleep
times 4.7 hours/day (SS ± 1.4) and average of daily
sleep efficiency 66.1% (SS 14.2). The results, carried
out with the body tracking monitor and based on
objectivedata,canpresentanevidenceofthereported
databythemaritimestudentsinthisstudy.
Studies in the literature
show that quality and
adequate nightʹs sleep are important in terms of
healthylifeandcognitiveperformanceandmayhave
animpactonacademicachievement(Zeeketal.2015,
Baertetal.2014,Koçoğluetal.2010,Eliasson&Lettieri
2010,Gilbert&Weaver2010,Perez‐Chadaetal.2007,
Howelletal.2004,Wagneretal.2004).Studentsinthe
sampleandinthewidespreadsysteminTurkeyneed
to continue their academic life at the end of the
internshipwithout interruption. The findings of this
study show that sleep quality of marine students is
negativelyaffectedbytheprocess
theyareworkingas
deck cadets. It has been observed that the students
didnotrecoverinnextamonthofreturningtoland
and they continued their education life by sleeping
problems.
5 CONCLUSION
When the data from this study and the data in the
literaturewereconsideredtogether,
itwasfoundthat
the marine university students had better sleep
quality(PSQIglobalscore:5.6±2.9)thanthestudents
inotheruniversitydepartmentsbeforetheinternship;
buttheyhadworsesleepqualityaftertheinternship
(PSQIglobalscore:7.6±3.5).
Third‐year students who were trained as a
oceangoingwatchkeepingofficerwere
foundtohave
a significant deterioration in sleep quality after
onboardtraining(mean6.9months).
Itwas observedthat thestudentswere subjectto
shift work procedures during onboard training but
continued to workoutside the shift (mean 15.4±2.4).
Students were generally in violation of STCW 78
(amended in 2010)
and MLC (2006) regulations as
deck cadets. Increased working hours have resulted
indecreasedrestandsleephoursandimpairedsleep
quality in the individual. As the training period
increased,thedeteriorationofsleepqualityincreased.
After the internship, daytime dysfunctions were
observed to increase significantly indicating the
seriousnessofthe
situation.
Additionally,thefindingthatthestudentsdidnot
recoverfromthecompromisedsleeppatternwithina
month after returning from the sea is also of
importancesincetheyhavecontinuetotheacademic
lifewiththisdisturbedsleeppattern.
Infuturestudies,itwouldbeusefultoreviewthe
attendance status and academic achievement of
marinestudentsaftertheinternship.Inaddition,the
effects of ship types, shift systems and training
periodscanbeexaminedinmoredetailbyincreasing
thenumberofsamples.
Itwouldbeusefultoreorganize theprograms of
themaritimeschoolssothattheyallow
the students
torecoverphysicallybeforethetransitiontoacademic
lifeaftertheinternship.Inaddition,firmsemploying
deck cadets should observe their working hours; it
willbeuseful todoworkarrangementsinsuchaway
thatnightrestswillnotbedividedandenoughsleep
can be attained
for at least 1 month before students
returntoland.
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