Psychological Distress Induces Poor Sleep Quality : A Cross-Sectional Study of Pharmacy Students in Bandung City , Indonesia

Results: The prevalence of psychological distress was well (43.1%), mild (28.6%), moderate (20.7%), and severe (7.6%). The overall sleep quality was poor and good in 84.5% and 15.5% of the students. There was a significant association between psychological distress and poor sleep quality (p=0.006). The multivariate analysis suggested that psychological distress was a predictor of poor sleep quality (OR 1.991; 95% CI, 1.311−3.026).


INTRODUCTION
Insufficient sleep, including short duration, irregular sleep schedules, and reduced sleep quality are common among college students [1,2].Sleep acts as a buffer in the normal line of defense against stress and illness [3].Previous studies have indicated that maintaining 7 to 8 hours of sleep is associated with the best health outcomes, whereas sleeping less or more is associated with poorer health status and increased risk of morbidity and mortality [4].The quality of sleep is a measure of both the quantitative and qualitative components of sleep [5].The quantitative component involves the duration of sleep whereas the qualitative component is a subjective measure of the depth and feeling of restfulness upon awakening [5].
Poor sleep quality has been closely related to mood disturbance and a number of risk factors for poor health outcomes [6], including high blood pressure, increased body mass index and depression [7].Moreover, insomnia, poor sleep quality, and short sleep have been found to be correlated with high stress [8,9].A previous study showed that increased stress and reduced health-related quality of life were observed in the first 3 years of a PharmD curriculum [10].Interestingly, the literature on stress and sleep deprivation indicates that there might be a bidirectional relationship between these two variables [11,12].
The Pittsburg Sleep Quality Index (PSQI) is used for subjective assessment of sleep quality [5].The Global Sleep Quality (GSQ) score is computed as the sum of response values for the seven components of the PSQI scale (sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbance, use of sleeping medication and daytime dysfunction) [5].These instruments are used as general measures of sleep health and daytime dysfunction, and are not specific for any single primary sleep disorder.The PSQI has been widely translated and used in a wide range of both population-based and clinical studies [13,14].
Very few studies have been conducted to explore the sleep quality of Indonesian undergraduate students.Most of these studies focused on sleep patterns and fatigue [15,16].Little is known about what factors contribute to poor sleep quality in this population.This study measures the association between psychological distress and poor sleep quality in a population of undergraduate students, and examines the factors that contribute to poor sleep quality.

METHODS
A cross-sectional survey was done in one of the universities of Bandung City, Indonesia.Assuming a prevalence rate of 32.5% [17] as the best estimate of poor sleep quality among undergraduate students, a minimum sample size of 290 would provide true values at 95% confidence interval (95% CI) level.Thus, data were collected from 290 undergraduate students.
This study was approved by the Universitas Padjadjaran Ethical Committee for Health Research (407/UN6.C1.3.2/KEPK/PN/2016).Informed consent was obtained from all undergraduate students after a full explanation of the purpose and procedures used for the study.All individuals who participated in this study signed informed consent forms (with anonymity and data confidentiality guaranteed), and all samples were taken in accordance with the Declaration of Helsinki [18].
The students were recruited by consecutive sampling to complete a self-administered questionnaire.They were asked to provide demographic information, such as age, gender, body weight, and height.In addition, they were required to report on their performance in college, such as their latest semester's cumulative Grade Point Average (cGPA).
The PSQI is commonly used for the subjective assessment of sleep quality [5].This instrument is a standardized quantitative measure of sleep quality with demonstrated high levels of consistency, reliability, and validity [5,21].The PSQI is a questionnaire consisting of 19 items that are coded on a 4-point scale (0-3) to obtain seven sub-categories, including sleep duration, sleep efficiency, sleep satisfaction, and medication use.The sum of all sub scores represents the total sleep quality score, ranging between 0 and 21, with higher scores representing lower sleep quality.The students were categorized as follows: good sleep quality (<5) and poor sleep quality (≥ 5).The students completed the Indonesian version of the PSQI.
Height and weight were measured using the self-reported questionnaire.Body Mass Index (BMI) was calculated as weight in kilograms divided by height in meters squared 2 (kg/m 2 ).The international classification of BMI was used.The principal cut-off points were categorized as follows: BMI ≥ 30 (obesity); BMI between 25 and 30 (overweight), BMI < 25 (normal weight), and BMI ≤ 18.5 (underweight) [22].
The descriptive results were expressed as frequency, percentage, and mean ± standard deviation.Kolmogorov-Smirnov test was used to check for normal distribution.Pearson's χ 2 analysis was used to assess the differences in the frequency distributions between variables.The statistical significance was set at p < 0.05.In the multivariate analysis, multinomial logistic regression was applied to investigate the associations between sleep quality and psychological distress while adjusting for demographics (age, gender and c GPA) and BMI.

RESULTS
A sample of 290 undergraduate students joined this study.Table 1 shows the socio-demographic information of the students.The students were predominantly female and ages 20 to 22 years old.Most students have normal BMI, are living alone, and receive tuition fee and life expenses from their parents.Two hundred forty-five students (84.5%) scored > 5 in the PSQI representing students with poor sleep quality, whereas 45 students (15.5%) scored ≤ 5 representing students with high sleep quality.There was a significant association between psychological distress and sleep quality (p=0.006).The prevalence of psychological distress was well (43.1%),mild (28.6%), moderate (20.7%), and severe (7.6%).The overall sleep quality was poor and good in 84.5% and 15.5% of the students, respectively (Fig. 1).
The multivariable-adjusted Odds Ratios (ORs) of psychological distress for the sleep quality are presented in Table 2.There was an increased likelihood of poor sleep quality score for those students with psychological distress (OR, 1.991; 95% C.I. 1.311 − 3.026).

DISCUSSION
The prevalence of poor sleep quality among the students in this study is 84.5%.This is much higher than the results of Suen [23] in the United States, who reported 42% and the findings of James [17] at a Nigerian University with 32.5%.The high rate of poor sleep quality in this study might also be due to the fact that the students took an exam afterwards.This is in concordance with the finding that academic schedules play an important role in the sleep disturbance of college students [24].
There was no significant association between sociodemographic information and BMI and sleep quality.This result is similar to the finding of previous studies among Malaysian tertiary students [25] and Estonian medical students [26].However, the result of this study is in contrast with the finding of Pearson et al., who found that obese patients have sleep difficulties [27].Further, the association of sleep quality with obesity was modified by perceived stress [28].The finding of this study might be due to the homogeneity of the students' BMI.
After multivariable adjustment, students with psychological distress had increased odds of reporting poor sleep quality (OR, 1.991; 95% CI, 1.311 − 3.026).Students with psychological distress were found to be 1.991 times more likely to have poor sleep quality compared to students without psychological distress.This result is in concordance with that of a previous study indicating that a higher global perceived stress is associated with poor sleep quality (r = 0.36) [6].In addition, a high degree of depression and anxiety was found to be the influencing factor of poor sleep quality among Chinese adolescents [29].
The effects of sleep disturbances in college students are substantial, such as an increased risk of mental illness [30], impaired social relationships [31], and reduced academic performance [32].In a previous study of a large population of college students, students with poor sleep quality reported significantly more problems of physical and psychological health than did students with good sleep quality [1].In addition, sleep deprivation has several adverse physiological consequences, including impaired glucose tolerance and insulin sensitivity, elevated sympathetic tone, increased inflammation, and the increase of ghrelin and decrease of leptin with the subsequent increase of hunger and appetite [1].
Psychological distress can serve as a predisposing, precipitating, and perpetuating factor of sleep difficulties in this population.First, college lifestyle creates precipitating factors that enhance stress-related sleeping difficulties (e.g., erratic schedules and high-stress periods such as final exams).Second, the students may be more susceptible to hyperarousal-related sleep difficulties because of the maturational changes in the neuroendocrine system.Third, college students may have not yet developed sufficient strategies for handling stressful events and subsequently may experience more internalizing and worry [33].Moreover, previous study showed that DNA methyltransferase 3A gene polymorphism contributes to daily life stress susceptibility among Indonesian healthy subject [34].Thus, biological factors may provide a predisposition for stress-induced sleep difficulties.Common stressful events in this population (e.g., midterm examinations and relationship troubles) and worry can accelerate sleep difficulties [1].
The current pharmacy curriculum emphasizes the importance of time and self-management skills due to the overload of the academic course (assignments, laboratories, presentations, and examination).According to the Accreditation Council for Pharmacy Education (ACPE), colleges and schools of pharmacy should actively investigate the students' levels of stress [35].Such analyses can be used in various stress management programs that could result in the elimination of certain stress-causing activities, possibly improving the students' overall health and academic performance.Only a few colleges and schools of pharmacy have published findings on student stress, especially from a 4-year PharmD curriculum [36].This finding may provide us the motivation needed to modify the curriculum to reduce psychological stress among college students.
This study had several limitations.First, the generalizability of this study may be limited since the study sample represented only for the selected student population.The subsequent studies should include a larger and more diverse group of students to ensure generalizability.Second, our data relied on the students' self-reported data and may have contained recall bias.In addition, there was no objective sleep assessment using polysomnography or actigraphy devices or stress symptoms collected clinically.However, the Kessler-10 and the PSQI are both validated measures and the most widely used self-reported measures of the psychological distress and sleep quality.Thus, it is unlikely that our estimates are seriously underestimated.

CONCLUSION
A large proportion of college students in one of the universities in Bandung City, Indonesia have poor sleep quality that is associated with psychological distress.There is a need for an awareness of the college resources and curriculum to help manage the stress levels of students through effective coping strategy-related study habits, time management, and self-management.

HUMAN AND ANIMAL RIGHTS
No Animals were used in this research.All human research procedures followed were in accordance with the ethical standards of the committee responsible for human experimentation (institutional and national), and with the Helsinki Declaration of 1975, as revised in 2008.

CONSENT FOR PUBLICATION
Written informed consent for publication was obtained from all participants.