© 2014 Harlina Halizah Siraj et al. This is an open access article distributed under the terms of the Creative Commons Attribution License -NonCommercial-
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Journal of Applied Pharmaceutical Science Vol. 4 (12), pp. 052-055, December, 2014
Available online at http://www.japsonline.com
Sleep pattern and academic performance of undergraduate medical
students at universiti Kebangsaan Malaysia
Harlina Halizah Siraj*, Abdus Salam, Raihanah Roslan, Nurul Ashiqin Hasan, Tan Hiang Jin, Muhammad Nazim
Department of Medical Education, Faculty of Medicine, University Kebangsaan Malaysia (UKM), Kuala Lumpur, Malaysia.
Received on: 21/03/2014
Revised on: 15/04/2014
Accepted on: 05/06/2014
Available online: 29/12/2014
Sleep is an active, repetitive and reversible state of perceptual disengagement from the environment including
unresponsiveness to it. Adequate sleep is extremely important for healthiness. But sleep
loss is a remarkable
problem in modern society. The obje
ctive of this study was to investigate the sleep pattern and its association
with students’ academic performance. It was a cross sectional study conducted among 4th
undergraduate medical students of session 2011-2012. Inclusive of all 234 registered 4th year students was
selected for this study. A standard questionnaire that contained questions on demography, sleep habits, academic
performance and ideal sleep was used to collect data. Out of 234 students, 186 were responded giving a respons
rate of 79.5% where 73% were female and 69% resided in-
campus. Including weekdays and weekends averagely,
56.2% respondents slept for 6-
8 hours, 29.1% for <6 hours and 14.7% slept for >8 hours. An average of 53.35%
respondents had in-frequent day-nap, 34.9% frequent and 11.75% had no day-
nap at all. Respondents who slept
>6 hours were observed to have significantly higher academic performance. It is concluded that, people need to
understand the role of sleep and have to take adequate sleep of 6-8 hours per day for health and wellbeing.
Sleep pattern, academic
Sleep is an active, repetitive and reversible state of
perceptual disengagement from the environment including
unresponsiveness to it (Carskadon and Dement, 2005). Children
and adolescents require an average sleep time of approximately 9
hours per night (Mercer et al., 1998). Sleep serves several different
functions such as growth and repair, learning or memory
consolidation and restorative processes and all these occur
throughout the brain and body (Krueger, 2003; Benington, 2000;
Curcio, 2006). So, adequate amount of sleep is fundamental for the
mental and physical health of an individual. (Kazim and Abrar,
2011; Mak et al., 2012). Cognitive functions related to academic
such as memory consolidation, learning, decision making and
critical thinking are all related with adequate sleep (Gilbert and
Weaver, 2010). Studies have shown that sleep deprivation can
cause psychiatric disorders and stress as well as dysfunctions such
* Corresponding Author
as decreased work efficiency and learning disability (Abdulghani
al., 2012; Eliasson et al., 2010). Sleep restriction studies on healthy
adults by restricting sleep below 7 hours per night suggest deficits
in cognitive functions (Durmer and Dinges, 2005).
It is mentioned that the association between sleep and
cognitive function is based on the idea that shortness or disruptions
of sleep reduces necessary overnight brain activity that is needed
for neurocognitive functioning which involves the prefrontal cortex
(Dahl, 1996). The consequence of insufficient sleep is the day time
sleepiness. Poor sleep quality, insufficient sleep and sleepiness are
significantly associated with worse school performance (Dewald et
Wolfson and Carskadon (1998), studied on 3000 high
school students showed that students with higher grades reported
more total sleep, earlier bedtimes on school nights and reduced
weekend delays of sleep schedules than students with lower grades.
Another study conducted on 3871 high-school students in Seoul,
showed students with poor sleep quality results is consequent
sharp increase in daytime sleepiness and it correlates significantly
with a decline in academic performance (Shin et al., 2003).
Siraj et al. / Journal of Applied Pharmaceutical Science 4 (12); 2014: 052-055 053
A significant correlation was seen between sleep qualities with
performance decrease reflecting attention deficit and compromised
executive control (Dahl, 1996; Jones and Harrison, 2001). Recent
studies in molecular genetics, neurophysiology and cognitive and
behavioural neurosciences reported that, sleep may play an
important role in memory consolidation and learning processes
(Siegel 2001; Smith, 2001; Hobson, 2002). Even then, sleep loss is
in fact one of the most striking problems of modern society
(Bonnet, 2000) and sleep deprivation is a common finding in
students’ academic life. In Malaysia, there are not many research
have been undertaken in the context of sleep pattern and academic
performance among the medical students. UKM medical faculty
being a leading national university, it is important to investigate
the students’ sleep pattern and their academic performance for
their health and wellbeing. The objective of this study was to
determine the relationship between sleep pattern and academic
performance of forth year UKM medical students as well as to
investigate the student perception about the ideal sleep time
necessary for good academic performance.
MATERIALS AND METHODS
This was a cross sectional study, conducted on 4th year
UKM undergraduate medical students during June 2011 to May
2012. The study group was selected by universal sampling
technique, inclusive of all 234 registered 4th year students.
A questionnaire was developed for data collection that
contains questions on demography, sleep habits including sleep
and wake-up time, total sleep hours, afternoon nap etc., during
weekdays and weekends. Their perception on ideal sleep duration
required for good academic performance was also recorded. The
questionnaire was pre tested by conducting a mini pilot study.
Academic performance was assessed by the cumulative
grade point average (CGPA) of semester-1 examination of year-4
students. The CGPA was calculated to a 5.0 scale. Consent was
taken from participants to participate in the study as well as to
disclose their CGPA. Each participant was asked to answer the
questionnaire in online software named survey monkey. All
answers were kept confidential. The data was the compiled and
analyzed using SPSS 13. Statistical analysis was done using
ANOVA and student t test.
Out of 234 medical students, 186 were responded, giving
the response rate of 79.5%. Table - 1 showed the demographic
data of the participants. Male participants were 27% whereas
female were 73% which is in keeping with the student distribution
of the institution. Among the participants, 69% resided in college
hostel or in-campus and 31 % resided out-campus.
Table - 2 showed the sleep duration pattern in weekdays
and weekends. On weekdays, 37.3% respondents slept <6 hours,
58.8% slept for 6-8 hours and 4% slept >8 hours. Meanwhile, on
weekends 20.9% of them slept <6 hours, 53.7% slept for 6-8 hours
and 25.4% slept >8 hours. Table - 3 showed the afternoon sleep in
weekdays and weekends. A total of 7.3% respondents did not take
afternoon snooze at all, 64.8% reported infrequent nap and 27.9%
reported frequent day napping during weekdays. On weekends
16.2% respondents did not take afternoon nap at all, 41.9%
infrequent and 41.9% frequently took day nap.
Table 1: Number (n) and percent (%) distribution of gender and residency of
the respondents, n=186.
Variables Number (n) Percent (%)
Gender Male 50 27
Female 136 73
Residency In Campus 128 69
Out Campus 58 31
Table 2: Distribution of respondents based on duration of sleep during
weekdays and weekends.
n (%) Weekends
<6 69 (37.3) 39 (20.9)
6-8 109 (58.8) 100 (53.7)
>8 8 (4.0) 47 (25.4)
Table 3: Respondents with day napping habits in weekdays and weekends.
Afternoon nap Weekdays
n (%) Weekends
Never 14 (7.3) 30 (16.2)
Infrequent (1-2 x per week) 120 (64.8) 78 (41.9)
Frequent (almost every day) 52 (27.9) 78 (41.9)
Table 4: Relationship between sleep duration and mean CGPA ± SD.
Sleep duration CGPA
Mean ± SD
Weekdays < 6 hours 3.050 ± 0.318
6 - 8 hours 3.084± 0.277
> 8 hours 3.000 ± 0.336
Weekends < 6 hours 2.92± 0.203
6 - 8 hours 3.09 ± 0.287
> 8 hours 3.12 ± 0.335
p = 0.033, for sleep duration between <6 hours and 6-8 hours in weekends
p = 0.028, for sleep duration between <6 hours and >8 hours in weekends
Table - 4 revealed the relationship between sleep duration and
CGPA. It is revealed that in weekdays, there was no significant
difference in the CGPA score between respondent with sleep <6
hours and respondent with sleep 6-8 hours and between
respondents with sleep 6-8 hours and respondent with sleep >8
hours. However, in weekend, there was significant difference of
CGPA score between respondent with sleep <6 hours and
respondent with sleep 6-8 hours (p=0.033) and more than 8 hours
(p=0.028). However, there was no significant difference between
respondent sleep 6-8 hours and more than 8 hours (p=0.871).
Table - 5 showed the relationship between day napping
and CGPA during weekdays and weekends. During weekdays, no
significant difference was found between respondent with never
had day napping and with had infrequent (p=0.649), and frequent
day napping (p=0.403); also there was no significant difference
between respondent with infrequent day napping and respondent
with frequent day napping (p=0.696). For weekends also, there
was no significant difference observed between respondent with
never had day napping and respondent with had infrequent
(p=0.970), and frequent day napping (p=0.883), and there was no
significant difference between respondent with infrequent day
et al. /
Journal of Applied Pharmaceutical Science 4 (12); 2014: 052-055
napping and respondent with frequent day napping (p=0.936).
Table - 6 revealed the student’s perception about ideal sleep
duration for better academic performance. Eighty seven percent
respondents reported that 6-8 hours sleep is necessary for better
Table 5: Relationship between day napping and CGPA ± SD during weekdays
Day napping Weekdays Weekends
Mean CGPA ± SD Mean CGPA ± SD
Never 2.980 ± 0.314 3.046 ± 0.318
Infrequent (1-2 x per week) 3.064 ± 0.281 3.064 ± 0.296
Frequent (almost every day) 3.111 ± 0.316 3.083 ± 0.285
Table 6: Students’ perception on necessary sleep duration for better academic
Necessary sleep duration for better
academic performance Responses
<6 hours 13 (7)
6-8 hours 162 (87)
>8 hours 11 (6)
Total 186 (100)
Optimized sleep pattern improves the neuro-cognitive
and academic performance of students (Curcio et al., 2006). But
sleep deprivation is a common finding in students’ academic life.
The sleep-wake cycle of medical students is characterized by
insufficient sleep duration, delayed sleep onset, and occurrence of
napping episodes during the day (Ng et al., 2009; Sweileh et al.,
2011). A local study in Malaysia mentioned that both medical
students and young doctors appear to accept that sleep deprivation
is norms to their medical training (Zailinawati et al., 2009).
Majority of the respondents in our study were female and
resided inside the campus (Table 1) where 37% of them had sleep
duration of <6 hours and only 4% students had sleep >8 hours
during the week days (Table 2). In general, most of the
respondents slept between 6-8 hours; however, there was an
increment of respondents who slept >8 hours from 4% on
weekdays to 25.4% on weekends (Table 2). This is most probably
due to the lack of time spent for sleeping in weekdays as the
respondents being busy with assignments and other academic
related requirements. Hence, the students tend to sleep more in
weekends to compensate their lack of sleep. The college life style
and the hostel environment also influences in the sleep pattern on
Sleep deprivation actually can cause day time sleepiness
and reduced level of attention affecting performance. Poor sleep
also affects performance by increasing depression, decreasing
motivation and compromising health (Kazim and Abrar, 2011;
Rocha et al., 2010). Twenty eight percent and 42% respondents in
this study found to have frequent day napping in weekdays and
weekends respectively (Table 3).
The present study indicated that the respondents with
sleep <6 hours during weekend have significantly lower CGPA
compared to the respondent with sleep 6-8 hours and >8 hours
(Table 4). Significant difference was observed between sleep
duration of <6 hours and 6-8 hours (p=0.033) and between <6
hours and >8 hours (p=0.028) in weekends with academic
performance in terms of CGPA (Table 4). However, it was not
significant during weekdays. This finding is similar to Curcio
(2006), who reported that a poor sleep in quality, quantity, sleep
loss and sleep deprivation showed to have relationship with
academic performance. A similar finding reported by Wolfson and
Carskadon, (1998) stated that student with higher grades reported
to had more total sleep and reduced weekend delays of sleep than
students with lower grades. Meanwhile, Carskadon (1990), Fallone
(2002) and Wolfson (2003) reported that a poor sleeping habit,
with an increased sleep fragmentation, later bedtimes and early
awakenings, usually tend to have a decreased academic
performance and a reduced neurobehavioral functioning. However
there are different studies that showed that no firm relationship
was found between the sleep duration and academic performance
(Kazim and Abrar, 2011). Day napping did not show any
significant role in academic performance in our study (Table 5).
Regarding the student perception of duration of ideal
sleep for better academic result, 87% student opined that 6-8 hours
sleep is necessary for better academic result (Table 6). But in
reality, less than 60% students slept 6-8 hours both in weekdays
and weekends (Table 2). In our study, more students found to go
bed lately during weekdays (Table 2) which is inconsistent with
the study done by BaHammam et al. (2012) where it was observed
that bed time was delayed in weekends. Delayed bed times in
weekends could be the expression of the college life style and
influence of hostel life. Even it could be related with circadian
rhythm disorders in the form of delayed sleep phase syndrome
marked by significant delays in sleep/wake cycles which is
common among college students (Buboltz, 2001).
Sufficient sleep is important for ones mental and physical
health (Kazim and Abrar, 2011). Insufficient sleep is a cause
emotional shakiness, memory loss, day time sleepiness and
decreased concentration (Kazim and Abrar, 2011; Rocha et al.,
2010). Necessities of sleep differ from person to person but 6-8
hours of sleep is considered normal for an adult (Kazim and
Abrar, 2011). Lack of adequate sleep affects the academic
performance of student (Kazim and Abrar, 2011).
Sleep loss is one of the most remarkable problems in
modern society. Sleep is extremely important for ones’ mental and
physical health and it plays an important role in learning processes
and memory consolidation. Lack of adequate sleep is a cause of
low academic performance. To achieve a better academic
performance, an adequate sleep of 6-8 hours per day is essential.
Students and educators need to understand the role of sleep for
better academic performance. Educators should pay attention to
counsel the students to make them more aware about the role of
sleep in their daily performance for academic achievement and
health and wellbeing. Further large scale study is suggested to
identify the variables of inadequate sleep.
Siraj et al. / Journal of Applied Pharmaceutical Science 4 (12); 2014: 052-055 055
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How to cite this article:
Harlina Halizah Siraj, Abdus Salam, Raihanah Roslan, Nurul
Ashiqin Hasan, Tan Hiang Jin, Muhammad Nazim Othman. Sleep
Pattern and Academic Performance of Undergraduate Medical
Students at Universiti Kebangsaan Malaysia. J App Pharm Sci,
2014; 4 (12): 052-055.