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Year : 2020  |  Volume : 9  |  Issue : 3  |  Page : 1662-1667  

The association of stress with sleep quality among medical students at King Abdulaziz University

1 Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
2 Department of Surgery, University of Jeddah, Jeddah, Saudi Arabia

Date of Submission07-Sep-2019
Date of Decision01-Feb-2020
Date of Acceptance12-Feb-2020
Date of Web Publication26-Mar-2020

Correspondence Address:
Maha A Safhi
Faculty of Medicine, King Abdulaziz University, Jeddah
Saudi Arabia
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jfmpc.jfmpc_745_19

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Objective: This study aims to determine the prevalence and the association of stress with sleep quality among medical students at King Abdulaziz University (KAU), Jeddah, Saudi Arabia. Methods: A cross-sectional study was done among 326 medical students of KAU using a stratified random sampling technique. An electronic self-administered questionnaire was used. Kessler Psychological Distress Scale (K10) and Pittsburgh Sleep Quality Index (PSQI) were used to assess the stress and sleep quality, respectively. Results: The overall students who experienced stress were 65%. The prevalence of poor sleep quality (total PSQI score ≥5) was 76.4%. There was a strong association between stress and poor sleep quality (value of Cramer's V = 0.371, P < 0.001), and it showed that the increase in stress level is a significant predictor of poor sleep quality. Conclusion: A high prevalence of stress and poor sleep quality was found among the students and the study confirms a strong association between them. We recommend establishing courses focusing on educating the students about proper sleep hygiene and how to deal with the stressful environment.

Keywords: Cross-sectional, medical students, Saudi Arabia, sleep disorders, stress

How to cite this article:
Safhi MA, Alafif RA, Alamoudi NM, Alamoudi MM, Alghamdi WA, Albishri SF, Rizk H. The association of stress with sleep quality among medical students at King Abdulaziz University. J Family Med Prim Care 2020;9:1662-7

How to cite this URL:
Safhi MA, Alafif RA, Alamoudi NM, Alamoudi MM, Alghamdi WA, Albishri SF, Rizk H. The association of stress with sleep quality among medical students at King Abdulaziz University. J Family Med Prim Care [serial online] 2020 [cited 2020 Aug 8];9:1662-7. Available from: http://www.jfmpc.com/text.asp?2020/9/3/1662/281209

  Introduction Top

Medical fields are considered to be a stressful area of education due to the high academic requirements and demanding professionals, the fact that shows a negative influence on both the mental and physical health of the students.[1],[2] Several factors contribute to this situation, including the academic overload, overnight on-call duties, contact with diseases and deaths, frequent examinations, and comprehensive curricula.[1],[3],[4],[5],[6] Furthermore, these students facing multiple stressors outside their medical school: physical, social, emotional, and family problems.[7],[8]

A large body of evidence supports the rising incidence levels of stress among medical students. Based on a systemic review done during 2006, medical students in Canada and the United States suffer from greater levels of suicidal ideation, depression, and psychological distress than the general community.[9] The prevalence of stress recorded as 20.9%, 41.9%, 90% in a Nepali, Malaysian, and Pakistani medical students, respectively.[10],[11],[12] In Saudi Arabia, stress prevalence documented as 63% and 53% in King Saud and King Faisal Universities, respectively.[13],[14] The potential adverse effects of psychological stress include impairment of the functioning performance of the students in the classroom and clinical practice, cognitive deficits, illness, increased the possibility of developing anxiety, depression, and reduced life satisfaction.[15],[16],[17] Poor health behaviors were also related to high-stress levels; students who experienced higher stress consumed more unhealthy food, less likely to get exercise, and more likely to get inadequate sleep. Consequently, physical, mental, behavioral, and academic difficulties were the cost of stress for students.[16]

The quality of sleep can be defined by both quantitative and qualitative components of sleep.

The quantitative part includes the duration of sleep, whereas the qualitative part is a subjective measure of the depth and feeling of restfulness upon awakening.[18] Reductions in sleep duration and sleep quality have unfavorable health consequences; resulting in increased morbidity and mortality.[19] Sleep difficulties can precipitate into several life dimensions, including mental, emotional, physical, social, academic, and professional problems. Among the general population, excessive and uncontrolled sleepiness is significantly associated with vocational accidents, work dismissal,[20],[21] and nearly seven times more road traffic accidents than people without any subjective fatigue or known sleep disorders.[22] Among the students, poor quality of sleep is strongly linked to emotional disturbance; feeling of anger, tension, depression, confusion and exhaustion; cognitive and memory dilemmas; and overall low life satisfaction.[23] Sleep deprivation considered as one of the most common causes of daytime sleepiness and tiredness; students go to bed late and has to wake up early; thus, they get insufficient sleep throughout the day. Sleep deprivation can arise from poor sleep behaviors, as the use of social media applications and technology before going to bed can also affect sleep quality adversely. Many students have poor sleep hygiene, which in combination with their delayed circadian rhythm, stimulate sleep deprivation.[24]

The rising levels of poor sleep quality and psychological distress have an adverse effect on mental and physical health.[25],[26] The long-term implications of this study will impact on identifying significant problems facing our students, which can eventually improve the healthcare quality provided by future doctors. Literature reviews have indicated that there were no recent studies that had been done before to investigate the association of sleep quality with stress among medical students at King Abdulaziz University (KAU). From our perspective, it is essential to evaluate the level of mental and physical health of our students and identify the gaps to enhance students' quality of life. Therefore, the objective of this study is to determine the prevalence and the association of stress and sleep quality among medical students at KAU, Jeddah, Saudi Arabia.

  Material and Methods Top

Study design and setting

A cross-sectional study was done at KAU during the academic year 2018 among medical students from the second to the sixth academic year. Students who have a history of psychiatric problems or being a visiting student at King Abdulaziz University Hospital (KAUH) were excluded.

Sample size and sampling procedure

The sample size required for this study was calculated as 326 participants for 95% confidence level and a margin of error of 5%, the calculations were made using the Raosoft sample size calculator.[27] We used a stratified random sampling technique. First, the proportion of students in each academic year was considered as a stratum. Then, randomly ask students in both female and male section to fill the questionnaire.

Data collection instruments

A standardized, anonymous questionnaire was used and distributed as an electronic form using Google forms and consisted of three parts: the first part inquired about demographic information, habits, and educational achievement. The second part was used to assess the stress using Kessler Psychological Distress Scale (K10), developed by Kessler and colleagues.[28] This instrument has been applied extensively in many epidemiological studies to estimate current (1-month) distress and severity associated with psychological symptoms. The K10 questionnaire was observed to have excellent psychometric properties with a Cronbach's α of 0.93, it composes of ten items; each item has five response categories: (1) “none of the time”; (2) “a little of the time”; (3) “some of the time”; (4) “most of the time”; and (5) “all of the time”. The scores ranged from 10 to 50 and classified according to the following: less than 20 are likely to be well, from 20 to 24 were classified as mild, from 25 to 29 were classified as moderate, 30 and more are likely to have severe stress.

The last part was to measure the quality of sleep using Pittsburgh Sleep Quality Index (PSQI),[18] which is the gold standard questionnaire for assessing subjective sleep quality and has been validated in both clinical and nonclinical populations.[29],[30] It has acceptable standards of test–retest reliability and validity.[18] A global PSQI score >5 yielded a diagnostic sensitivity of 89.6% and specificity of 86.5% (kappa = 0.75, P < 0.001) in defining good and poor sleepers. This questionnaire investigates seven components; sleep quality, sleep latency, sleep duration, habitual sleep efficiency, step sleep disturbances, use of sleeping medication, and daytime dysfunction. The seven component scores of the PSQI had an overall reliability coefficient (Cronbach's α) of 0.83, indicating a great degree of internal consistency.[18] The questionnaire composed of 19 self-rated questions and five questions rated by the bed partner or roommate (if available). Only, self-rated questions are included in the scoring. Each component has a score range of 0 to 3; 0 indicates no difficulty, whereas 3 indicates sever sleep difficulty. The seven component scores are then added to one global score, which ranges from 0 to 21, where “0” indicates no difficulty at all and “21” indicates severe difficulties.


Microsoft Excel 2016 was used for data entry and statistical analysis was performed using IBM© SPSS© Statistics version 21 (IBM© Corp., Armonk, NY, USA). Frequencies and percentages were done for the categorical variables and measures of central tendency were calculated for the continuous variables. Analysis of variance, independent-samples t-test, and Chi-Square test of independence were used in the analysis. Binary logistic regression was used to determine the predictors of sleep quality and to calculate the odds ratio (OR) and 95% confidence intervals (95% CI). All P value < 0.05 were considered statistically significant.

Research ethics

This study was approved by the biomedical ethical committee at KAUH (Ref: 386-18). All participants were notified about the study objectives and response confidentiality and we took their consent.

  Results Top


The total responses were 326 medical students that responded and completed the questionnaire, 50.6% of them were males. The mean age of the participants was 21.86 ± 1.7 years. Students' demographics demonstrated in [Table 1].
Table 1: Students' demographics

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The mean stress score among the students was 25 ± 8.66, and the overall students who experienced stress were 65%, 18.7% of them had mild stress, 15% had moderate stress, and 31.3% had severe stress. There was a reduction in the stress scores as the year of study increased except for the final year (P = 0.016). There was no statistically significant difference between stress level and gender (P = 0.175), marital status (P = 0.466), living with family (P = 0.66), or consumption of caffeine beverages (P = 0.682). Further analysis did not find any statistical significance between stress and Grade Point Average (GPA) (P = 0.707, F value = 0.465).

Quality of sleep

The mean global PSQI score was 7.41 ± 3.66. The prevalence of poor sleep quality (total PSQI score ≥ 5) was 76.4% (n = 2 49). The students who estimated their sleep quality as very good sleep quality were 41 (12.6%), fairly good 150 (46%), fairly bad 94 (28.8%), very bad 41 (12.6%) students. Of the PSQI, the subjective sleep quality, sleep latency, sleep duration, and use of medications are shown in [Table 2]. There was a significant difference between sleep quality and caffeine consumption (P = 0.007). Otherwise, there was no apparent significant difference with sleep quality and the academic year (P = 0.693) nor living with family (P = 0.067). Further analysis did not reveal any statistical significance between the quality of sleep and GPA (P = 0.413).
Table 2: PSQI components

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The Chi-square test of independence showed a strong association between stress and poor sleep quality (value of Cramer's V = 0.371, P < 0.001). Logistic regression showed that Kessler score was a significant predictor of PSQI score (β =0.155; OR = 1.167; 95% CI 1.036—1.315; P = 0.011).

It showed that the increase in stress level is a significant predictor of poor sleep quality and that 74.4% of poor sleepers were in stress, whereas 56.1% of nonstressed students were poor sleepers. [Table 3] demonstrates the relationships between sleep quality, stress levels, and sociodemographic variables of the students.
Table 3: Relationships between sleep quality, stress levels, and sociodemographics of medical students at King Abdulaziz University

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  Discussion Top

This study highlights the high prevalence of psychological distress (65%) and poor sleep quality (76.4%) among the medical students at KAU. When compared with other studies, our results demonstrate a higher prevalence of stress than a Pakistani medical school (59.7%) and King Saud University (53.2%), respectively.[1],[25] However, it appears to be less than other Pakistani and Indian medical schools who describe that more than 90% of their students suffered from stress.[12],[31] A possible explanation for this variation might be due to using different stress assessment instruments. It is well known that during the medical training, the students facing multiple stressors and challenges,[32],[33] if these challengeable difficulties left and neglected, they will contribute to further stresses.[9] Medical training itself considered as a risk factor in developing depressive symptoms,[34],[35],[36] which may explain the increased levels of stress among the students.

Consistent with previous studies, the current study confirms the rising prevalence of poor sleep quality among medical students. There are several possible factors explained this result, medical students have various activities, and they are also handling multiple stressors, which may lead them to study during the night.[1],[25],[26],[37],[38]

This study also confirms that stress level is significantly associated with poor sleep quality. It demonstrates that the high level of stress is a significant predictor for the poor quality of sleep, in line with recent studies conducted at King Saud University, and a Pakistani medical school.[1],[25] Psychological distress considered as a triggering factor for sleep disturbance.[39] In response to stressors, physiological changes take place to help the body coping with the situation.[40] However, chronic activation of these stress responses, which include the sympathetic–adrenal–medullary axis and the hypothalamic–pituitary–adrenal axis, can give rise to the persistent production of epinephrine and cortisol, which called “stress hormones.”[21],[41],[42] Similarly, sleep deprivation can affect the circadian rhythm of cortisol secretion.[42] Therefore, it represents a vicious cycle that has a negative effect on the mental health of the students.[1]

The current study showed no gender dominance within stress or sleep quality, which coincides with two recent studies.[1],[25] In the Faculty of Medicine, KAU, the examinations, and requirements are the same for both campuses, so there are no differences between females and males. Contrary to the findings of our study, some studies have reported that female students have worse stress levels,[43],[44] and sleep disorders.[45] However, the cross-sectional design of this study limits details analysis of gender difference.

Interestingly, our results revealed no significant association between stress level and GPA, which goes in agreement with a study published at King Saud University in 2018.[44] The precise cause of such a result is difficult to understand and could not be explained by this study. However, this could be due to the students who have been able to develop a coping mechanism and adaptation despite their grades. Abdulghani et al. illustrated a conflicting relationship between the academic level and stress.[13] Similarly, the current study demonstrates that the stress levels decreased as the academic level increased except for the final year. This could be due to the study design of this study is not a longitudinal study and limit the assurance of decreasing stress levels of the participants.

Concerning hygienic sleep habits, our results confirm that poor sleepers reported greater caffeine consumption in comparison with good sleepers. This finding agrees with two recent studies conducted in Saudi Arabia and South Australia.[37],[46] In excess, caffeine can lead to a disruption of sleep; depending on the consumed amount, it has both positive and negative behavioral and cognitive effects.[47] Consumption of caffeine beverages markedly reduces sleep time, prolong the bedtime and overall disrupts the quality of sleep.[48],[49]

The present study makes several significant and noteworthy findings; however, in the cross-sectional studies, there is a potential for reporting bias as this study was based on a self-administrated questionnaire filled by the students. Also, the validation of GPA records was a limitation.

  Conclusion Top

The current study found a high prevalence of stress and poor quality of sleep among medical students with a significant association between them. Medical students suffer from poor sleep quality and chronic stress that will lead to unhealthy behaviors like consuming a lot of unhealthy food and less likely to exercise. Incontestably, they are more susceptible to have chronic diseases. If these problems neglected, it will reflect on the health care provided to their future patients. As part of primary health care practice is to prevent and detect the risk factors of the diseases. Accordingly, we recommend providing adequate support and counseling, guidance, and mental health prevention programs for undergraduate students as part of their clinical rotations. Another longitudinal study could be conducted to identify the stress levels and quality of sleep among undergraduate students in the medical school and the associated factors.


This study was part of the research summer school 2018 project, under the supervision of Road Of Change team, which is an institute for teaching people research. The authors would like to thank them for supporting this paper. No financial support was needed. The authors appreciate the medical students of KAUH; Maha K. Alghamdi, Ammar J. Kabbarah, and Mohammed A. Safhi for their efforts in data collection. The authors also thank Dr. Mohammed R. Algethami for the critical revision of this research.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Waqas A, Khan S, Sharif W, Khalid U, Ali A. Association of academic stress with sleeping difficulties in medical students of a Pakistani medical school: A cross sectional survey. Peer J 2015;3:e840.  Back to cited text no. 1
Sethia R, Sharma G, Shekhawat K, Aacharya A, Acharya R, Meena RR. Study of perceived stress and stressors among undergraduate medical students. Int J Community Med Public Health 2019;6.  Back to cited text no. 2
Wong J, Patil N, Beh S, Cheung E, Wong V, Chan L, et al. Cultivating psychological well-being in Hong Kong's future doctors. Med Teach 2005;27:715-9.  Back to cited text no. 3
Wear D. “Face-to-face with it”: Medical students' narratives about their end-of-life education. Acad Med 2002;77:271-7.  Back to cited text no. 4
MacLeod RD, Parkin C, Pullon S, Robertson G. Early clinical exposure to people who are dying: Learning to care at the end of life. Med Educ 2003;37:51-8.  Back to cited text no. 5
Guthrie E, Black D, Bagalkote H, Shaw C, Campbell M, Creed F. Psychological stress and burnout in medical students: A five-year prospective longitudinal study. J Royal Soc Med 1998;91:237-43.  Back to cited text no. 6
Fish C, Nies MA. Health promotion needs of students in a college environment. Public Health Nurs 1996;13:104-11.  Back to cited text no. 7
Chew-Graham CA, Rogers A, Yassin N. 'I wouldn't want it on my CV or their records': Medical students' experiences of help-seeking for mental health problems. Med Educ 2003;37:873-80.  Back to cited text no. 8
Dyrbye LN, Thomas MR, Shanafelt TD. Systematic review of depression, anxiety, and other indicators of psychological distress among US and Canadian medical students. Acad Med 2006;81:354-73.  Back to cited text no. 9
Sreeramareddy CT, Shankar PR, Binu V, Mukhopadhyay C, Ray B, Menezes RG. Psychological morbidity, sources of stress and coping strategies among undergraduate medical students of Nepal. BMC Med Educ 2007;7:26.  Back to cited text no. 10
Sherina MS, Rampal L, Kaneson N. Psychological stress among undergraduate medical students. Medical Journal of Malaysia 2004;59:207-11.  Back to cited text no. 11
Shaikh BT, Kahloon A, Kazmi M, Khalid H, Nawaz K, Khan N, et al. Students, stress and coping strategies: A case of Pakistani medical school. Educ Health (Abingdon) 2004;17:346-53.  Back to cited text no. 12
Abdulghani HM, AlKanhal AA, Mahmoud ES, Ponnamperuma GG, Alfaris EA. Stress and its effects on medical students: A cross-sectional study at a college of medicine in Saudi Arabia. J Health Popul Nutr 2011;29:516.  Back to cited text no. 13
Rahman AA, Al Hashim B, Al Hiji N, Al-Abbad Z. Stress among medical Saudi students at college of medicine, King Faisal University. J Prev Med Hyg 2013;54:195.  Back to cited text no. 14
Malathi A, Damodaran A. Stress due to exams in medical students-a role of Yoga. Indian J Physiol Pharmacol 1999;43:218-24.  Back to cited text no. 15
Brougham RR, Zail CM, Mendoza CM, Miller JR. Stress, sex differences, and coping strategies among college students. Current Psychol 2009;28:85-97.  Back to cited text no. 16
Azim SR, Baig M. Frequency and perceived causes of depression, anxiety and stress among medical students of a private medical institute in Karachi: A mixed method study. JPMA J Pakistan Med Assoc 2019;69:840-5.  Back to cited text no. 17
Buysse DJ, Reynolds CF III, Monk TH, Berman SR, Kupfer DJ. The Pittsburgh sleep quality index: A new instrument for psychiatric practice and research. Psychiatry Res 1989;28:193-213.  Back to cited text no. 18
AlDabal L, BaHammam AS. Metabolic, endocrine, and immune consequences of sleep deprivation. Open Respir Med J 2011;5:31.  Back to cited text no. 19
Guilleminault C, Carskadon M. Relationship between sleep disorders and daytime complaints. Sleep 1977;3:95.  Back to cited text no. 20
Li Y, Gu S, Wang Z, Li H, Xu X, Zhu H, et al. Relationship between stressful life events and sleep quality: Rumination as a Mediator and Resilience as a Moderator. Front Psychiatry 2019;10:348.  Back to cited text no. 21
Findley L, Unverzagt M, Guchu R, Fabrizio M, Buckner J, Suratt P. Vigilance and automobile accidents in patients with sleep apnea or narcolepsy. Chest 1995;108:619-24.  Back to cited text no. 22
Pilcher JJ, Ginter DR, Sadowsky B. Sleep quality versus sleep quantity: Relationships between sleep and measures of health, well-being and sleepiness in college students. J Psychosom Res 1997;42:583-96.  Back to cited text no. 23
Hershner SD, Chervin RD. Causes and consequences of sleepiness among college students. Nature Science Sleep 2014;6:73.  Back to cited text no. 24
Almojali AI, Almalki SA, Alothman AS, Masuadi EM, Alaqeel MK. The prevalence and association of stress with sleep quality among medical students. J Epidemiol Global Health 2017;7:169-74.  Back to cited text no. 25
Satti MZ, Khan TM, Qurat-Ul-Ain QU, Azhar MJ, Javed H, Yaseen M, et al. Association of physical activity and sleep quality with academic performance among fourth-year MBBS students of Rawalpindi Medical University. Cureus 2019;11:e5086.  Back to cited text no. 26
Raosoft. Sample size calculator 2004. Available from: http://www.raosoft.com/samplesize.html. [Cited 2018 Jul 05].  Back to cited text no. 27
Kessler RC, Andrews G, Colpe LJ, Hiripi E, Mroczek DK, Normand SL, et al. Short screening scales to monitor population prevalences and trends in non-specific psychological distress. Psychol Med 2002;32:959-76.  Back to cited text no. 28
Carney CE, Edinger JD, Meyer B, Lindman L, Istre T. Daily activities and sleep quality in college students. Chronobiol Int 2006;23:623-37.  Back to cited text no. 29
Backhaus J, Junghanns K, Broocks A, Riemann D, Hohagen F. Test–retest reliability and validity of the Pittsburgh Sleep Quality Index in primary insomnia. J Psychosom Res 2002;53:737-40.  Back to cited text no. 30
Gupta S, Choudhury S, Das M, Mondol A, Pradhan R. Factors causing stress among students of a Medical College in Kolkata, India. Educ Health 2015;28:92.  Back to cited text no. 31
[PUBMED]  [Full text]  
Dahlin M, Joneborg N, Runeson B. Stress and depression among medical students: A cross-sectional study. Med Educ 2005;39:594-604.  Back to cited text no. 32
Castaldelli-Maia JM, Martins SS, Bhugra D, Machado MP, De Andrade AG, Alexandrino-Silva C, et al. Does ragging play a role in medical student depression—cause or effect? J Affect Disord 2012;139:291-7.  Back to cited text no. 33
Kawada T, Katsumata M, Suzuki H, Shimizu T. Actigraphic predictors of the depressive state in students with no psychiatric disorders. J Affect Disord 2007;98:117-20.  Back to cited text no. 34
Jeon HJ, Roh M-S, Kim K-H, Lee J-R, Lee D, Yoon SC, et al. Early trauma and lifetime suicidal behavior in a nationwide sample of Korean medical students. J Affect Disord 2009;119:210-4.  Back to cited text no. 35
Ahaneku JE, Nwosu CM, Ahaneku GI. Academic stress and cardiovascular health. Acad Med 2000;75:567-8.  Back to cited text no. 36
Ibrahim N, Badawi F, Mansouri Y, Ainousa A, Jambi S. Sleep quality among medical students at King Abdulaziz University: A cross-sectional study. J Community Med Health Educ 2017;7:2161-711.  Back to cited text no. 37
Lemma S, Gelaye B, Berhane Y, Worku A, Williams MA. Sleep quality and its psychological correlates among university students in Ethiopia: A cross-sectional study. BMC Psychiatry 2012;12:237.  Back to cited text no. 38
Suchecki D, Machado RB, Tiba PA. Stress-induced sleep rebound: Adaptive behavior and possible mechanisms. Sleep Sci 2009;2:151-60.  Back to cited text no. 39
Padgett DA, Glaser R. How stress influences the immune response. Trends Immunol 2003;24:444-8.  Back to cited text no. 40
Hall JE. Pocket Companion to Guyton and Hall Textbook of Medical Physiology E-Book. Elsevier Health Sciences; 2015.  Back to cited text no. 41
Leproult R, Copinschi G, Buxton O, Van Cauter E. Sleep loss results in an elevation of cortisol levels the next evening. Sleep 1997;20:865-70.  Back to cited text no. 42
Shah M, Hasan S, Malik S, Sreeramareddy CT. Perceived stress, sources and severity of stress among medical undergraduates in a Pakistani medical school. BMC Med Educ 2010;10:2.  Back to cited text no. 43
Hamad Alsalhi A, Almigbal T, Hamad Alsalhi H, Batais M. The relationship between stress and academic achievement of medical students in King Saud University: A cross-sectional study. ABSTRACT2018. 60-5 p.  Back to cited text no. 44
Abdulghani HM, Alrowais NA, Bin-Saad NS, Al-Subaie NM, Haji AM, Alhaqwi AI. Sleep disorder among medical students: Relationship to their academic performance. Med Teach 2012;34(Suppl 1):S37-41.  Back to cited text no. 45
Watson E, Coates A, Kohler M, Banks S. Caffeine consumption and sleep quality in Australian adults. Nutrients 2016;8:479.  Back to cited text no. 46
Březinová V. Effect of caffeine on sleep: EEG study in late middle age people. Br J Clin Pharmacol 1974;1:203-8.  Back to cited text no. 47
Hindmarch I, Rigney U, Stanley N, Quinlan P, Rycroft J, Lane J. A naturalistic investigation of the effects of day-long consumption of tea, coffee and water on alertness, sleep onset and sleep quality. Psychopharmacology 2000;149:203-16.  Back to cited text no. 48
AlSharif SM, Al-Qathmi MS, Baabdullah WM, Alhrkan TA, Fayoumi YA, Alhejaili FF, et al. The effect of caffeinated beverages on sleep quality in college students. Saudi J Intern Med 2018;8:43-8.  Back to cited text no. 49


  [Table 1], [Table 2], [Table 3]


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